THE INFLUENCE OF PHYSICAL EXERCISE
ON EMPLOYEES’ SKILLS IN CREATIVE
THINKING
Tom Steffens
January 2010
University of Groningen
Faculty of Economics and Business MsC BA Strategy & Innovation Nettelbosje 2
Groningen, 9747 AE Tel: (050) – 363 3741 Fax: (050) – 363 7970
THE INFLUENCE OF PHYSICAL EXERCISE ON
EMPLOYEES’ SKILLS IN CREATIVE THINKING
ABSTRACT
This study analyzes whether physical exercise can positively influence employees’ skills in creative thinking. Next to an extensive literature research, a true experimental research design was administered, consisting of pre- and post measurement and a randomly assigned experimental and control group. After exercising twice a week during a month, respondents from the experimental group significantly improved their performance on ‘Fluency’ on TTCT task ‘Repeated figures’. This improvement was significantly higher then reported improvement of performance on ‘Fluency’ on the same task by respondents from a control group. Finally, regression-analysis showed improved performance to occur independently of increased physical fitness or improved mood.
Key words: physical exercise, skills in creative thinking, organizational innovation, creative performance
CONTENTS ABSTRACT ...2 CONTENTS ...3 INTRODUCTION ...4 Research question...5 Sub-questions ...5 Thesis outline...5 LITERATURE REVIEW ...6
Innovation and creativity ...6
Innovation ...6
Connection between innovation and creativity ...8
Individual and small-group creativity...10
Creativity ...10
Individual and small-group creative performance...11
Creativity-relevant skills (Skills in creative thinking) ...13
Influence of physical exercise on skills in creative thinking...14
Influence of physical exercise on cognition...14
Influence of physical exercise on creativity...17
CONCEPTUAL MODELS ...21
Dependent variable: Skills in creative thinking ...23
Independent variables...24
Chronic physical exercise ...24
Individual physical fitness ...24
Mood...24
METHODOLOGY...24
Internal validity of the research design...26
External validity of the research design...26
Measurement tool: The Torrance Test for Creative Thinking ...26
Validity...27
Reliability ...27
Practicality ...28
RESULTS...28
Chronic physical exercise and skills in creative thinking...28
Mood and skills in creative thinking ...33
Level of individual physical fitness...35
CONCLUSION AND DISCUSSION ...38
LIMITATIONS...40
DIRECTIONS FOR FURTHER RESEARCH ...41
LITERATURE...43
APPENDIX A: PRE-TEST TTCT-VERBAL AND TTCT-FIGURAL...48
APPENDIX B: POST-TEST TTCT-VERBAL AND TTCT-FIGURAL...49
APPENDIX C: MOOD ADJECTIVE LIST...52
INTRODUCTION
Innovation is key in pretty much any modern day industry. The growing need to differentiate, in order to maintain current market position and gain new markets, places innovation at the heart of most companies’ strategies (Christensen, 1997). Companies are faced not only with the pressure to introduce new, innovative products or services, but also to do so in a rate faster than the competition. Next to product innovation, process innovation or developing a firm’s processes and operations in a visionary innovative way, is just as important. “Being able to make something no one else can, or to do so in ways which are better than anyone else is a powerful source of advantage” (Tidd, Bessant & Pavitt, 2001).
In a business context, innovation can be best described as the commercialization of an invention, or bringing an idea ‘to the market’. In essence, all innovation starts with creative ideas (Amabile et al., 1996) (Ekvall, 1997) and accordingly, creativity and the innovativeness of an organization can be regarded to be heavily dependent on the ability of individual employees (and teams of employees) to generate novel, good, and useful ideas and implement these ideas successfully. Many studies have tried to identify factors that could influence employees’ creative performance. For example, several studies found that a company’s social, cultural and managerial environment can play an important role in people’s willingness to express their creativity (Amabile, 1988; Amabile et al, 1996; Damanpour, 1991; Ekvall, 1997). From an interview study, Amabile (1988) identified nine various organizational characteristics of work environments (e.g. freedom, sufficient resources, encouragement, sufficient time, challenge and recognition) which served to promote creativity while several other characteristics were found to inhibit creativity (e.g. inappropriate reward systems, lack of cooperation across divisions and levels, organizational disinterest, insufficient resources, time pressure, overemphasize on the status quo, and competition) (Amabile, 1988).
Finally, several researchers have been trying to identify a relationship between physical exercise and creative performance (Blanchette et al., 2005; Gondola & Tuckman, 1985; Ramocki, 2002; Steinberg et al., 1997). Gondola and Tuckman (1985) for example, identified a strong influence between a systematic program of running and creativity. In general, many of these studies acknowledge that organizations may potentially benefit from employees’ improved creative performance through physical exercise: “fostering environments that encourage aerobic exercise for employees may yield increases in creative output and innovation in product development, promotion, operations management, and many other areas” (Blanchette et al., 2005).
Research question
This paper will elaborate on the proposed relationship between physical exercise and creative performance of companies’ individual employees. In doing so, the following research question shall be addressed:
• Can physical exercise positively influence skills in creative thinking of individual employees?
Sub-questions
In order to answer the research question, the following sub-questions shall be explored:
• How can creative performance of individual employees be related to an organization’s innovativeness?
• What knowledge exists regarding the relationship between physical exercise and the creative performance of a company’s individual employees?
• According to academic literature, how can the concept of individual creative performance be operationalized and measured?
• According to academic literature, what type and duration of physical exercise can be best used in an empirical analysis of the relationship between physical exercise and creative performance of individual employees?
• After following a program of physical exercise, will individual employees demonstrate improved creative performance?
• When improved creative performance after physical exercise indeed occurs, can this be explained by improvements in an individual’s level of physical fitness or mood?
Thesis outline
of organizational innovation. Also, the concept of skills in creative thinking, based on Amabile’s (1988) theories on creative performance, will be introduced. Next, a review of prior literature on the topics of physical fitness and cognition shall be presented. As shall be discussed in this thesis, creativity is strongly related to cognition, the process by which knowledge and understanding is developed in the (human) mind (Hornby, 2005). Prior studies on connections between physical exercise and cognitive performance of individuals will be analyzed in order to shape a picture of how physical exercise may influence processes in the human mind in general. Next step is to narrow the scope, zoom in on cognitive processes, and look specifically at possible relationships between physical exercise and creativity. Final product of the literature review will be a conceptual model which will provide the foundation for the second, experimental part of this research. Fifteen employees of several companies, during a month, participated in a 60-minute workout twice a week. Before and after, creative tests were conducted in order to see whether participating in a chronic physical exercise program increased individuals’ skills in creative thinking. Generated data shall be analyzed, results shall be presented, and conclusions shall be drawn. Finally, a discussion and directions for further research are presented.
LITERATURE REVIEW
Innovation and creativity
As stated in the introduction of this thesis, innovation is of crucial importance to most modern day companies. But how exactly is innovation related to economics and why does it play such an essential role in modern corporate life? Also, how does an innovation become an innovation? What are its origins?
Innovation
In general terms, innovation means the introduction or implementation of new things, ideas or ways of doing things. An important distinction between invention and innovation has to be made here. In essence, an innovation is the commercial implementation of an invention; an invention only becomes an innovation when it has proceeded through production and marketing tasks and is diffused into the marketplace (Garcia & Calantone, 2002). In other words, “an innovation differs from an invention in that it provides economic value and is diffused to other parties beyond the discoverers” (Garcia & Calantone, 2002).
organizational innovation ever since. Schumpeter proposes that innovation causes most markets to evolve in a characteristic pattern. Periods of relative stability, in which companies that have developed superior products, services, organizational capabilities or technologies earn monopoly profits, are disturbed by fundamental discontinuities created by a new, radical innovation. Old sources of competitive advantage are being destroyed and replaced by new ones. In turn, companies that efficiently exploit the opportunities created by these shocks, can achieve monopoly profits during the next period of relative quite and stability. The ability to act on the opportunities innovations create is the true essence of competitive advantage (Schumpeter, 1934) (Besanko et al., 2004).
The importance of innovation for organizations is stretched by Abernathy and Clarke (1984), who state that competitive advantage depends on the acquisition or development of particular resources, skills, knowledge, and relationships. Innovations can affect these requirements in different ways: “some innovations disrupt, destroy, and make obsolete established competence; others refine and improve” (Abernathy & Clarke, 1984). The significance of an innovation for competitive advantage is thus its capacity to affect the firm’s existing knowledge, resources, and skills. Abernathy and Clarke (1984) labelled this capacity “transilience”.
Finally, Tidd et al. (2001) propose several ways in which innovation contributes to competitive advantage. First, new products or services help capture and retain market shares, and increase profitability (Tidd et al., 2001). Second, being able to replace products frequently with better versions is increasingly important in a world of shortening product life cycles. Importantly, Tidd et al. (2001) state that process innovations can be just as important; “being able to make something no one else can, or to do so in ways which are better than anyone else is a powerful source of advantage” (Tidd et al., 2001).
Next to stretching the importance of innovation, many academics have dealt with attempts to identify, categorize, describe and explain particular innovative products, services, and processes. For example, Garcia and Calantone (2002) identify an innovation as radical, really new, or incremental, while Jacobs (2007) makes a distinction between product/service innovation, process innovation, transaction innovation, an system innovation (Jacobs, 2007).
organizations to innovate and produce innovative products (Orosa Paleo & Wijnberg, 2008)(Garcia & Calantone, 2002). Several authors have studied organizational innovation. Important distinction here is that some have taken an ex-ante perspective, trying to identify factors that could predict an innovative performance of a particular firm (Amabile,1983) (Amabile, 1988)(Hurley et al.,2005), while others looked at organizational innovation from an ex-post perspective, studying the results and consequences of innovations to determine whether a particular organization can be considered to be innovative (Garcia & Calantone, 2002) (Orosa Paleo & Wijnberg, 2008). As will become clear further on in this article, the ex-ante organizational innovation perspective will be the most relevant for this study. It looks at properties of individuals (and groups), characteristic for individual (and group) idea generation, learning, creativity, and change, and influencing a firm’s capacity and potential to innovate (Hurley et al.,2005).
Connection between innovation and creativity
So how does an innovation originate? Many academics have stretched the strong dependence of organizational innovation on individual and small group creativity, stating that all innovation initially springs from a creative idea (Kanter, 1983)(van de Ven, 1986)(Amabile, 1988)(Amabile et al., 1996)(Ekvall, 1997)(Hurley et al.,2005). Most of this prior work on innovation and creativity regard the generation of creative ideas as an individual activity, while the actual transformation or implementation of the idea into an innovation is most often a collective effort (Kanter, 1983)(van de Ven, 1986)(Ekvall, 1997)(Hurley et al.,2005). Amabile (1988) takes a slightly different approach, stating that “creativity is the production of novel and useful ideas by an individual or small group of individuals working together” (Amabile, 1988). Contrary to the authors stated above, she does not explicitly distinguish between individual idea generation and collective idea implementation. In her opinion, initial generation of creative ideas can both be an individual and a small team effort. Just looking at the widespread use of brainstorming in organizations to generate ideas or solve problems (Kaufman and Sternberg, 2006), she has a solid point here.
The first stage of the innovation process, setting the agenda, entails presentation of a mission statement for the organization, which sets an overall direction. Secondly, the stage is set, which includes specifying the mission statement in more clear, concrete project goals. At this stage, “the organization is mobilized to enable creative idea-generation to take place”(Amabile, 1988). Next, the third stage represents the actual generation of ideas. It is in this stage that individuals or small groups produce the ideas that form the basis of an innovation. In the fourth stage, the generated ideas are tested and implemented. The fifth stage entails outcome assessment. Here, preliminary attempts at implementing the idea are being evaluated. The innovation process ends when there is complete success (a new product, process, or service is successfully produced) or complete failure (no reasonable ideas were generated for implementation or implementation yielded no progress). When there is some progress, some evidence of “getting warmer”(Amabile, 1988), the innovation process may cycle back to stage 2, in which the approach to finding innovative solutions, products, services etc. is reformulated.
Figure 1 (part of) Amabile’s model of organizational innovation
management (Amabile, 1988). For example, innovation management and resources in the task domain play an important role in stage 2, ‘setting the stage’, as the requirements for generating creative ideas (communication channels, autonomy, reward systems etc.) need to be taken care of and required resources (money, people, systems, information etc.) need to be put in place. In essence, Amabile points to an interdependent relationship between individual and organization: “there will be no innovation in an organization without creative ideas from individuals”…[while simultaneously]…“individual creators are significantly influenced by what happens in the organization”(Amabile, 1988).
So far, we can conclude that innovative performance of an organization can be regarded to depend heavily on the ability of individual employees and teams of employees to generate good and useful ideas and implement these ideas successfully. Amabile’s model (1988) helps to place this thesis in the right context. By illustrating the crucial role of creativity within the process of organizational innovation, it provides a strong argument for this article to zoom in and focus on the specific stage of individual and small group creativity.
Individual and small-group creativity Creativity
Defining the ambiguous terms creativity has been a puzzle many academics tried to solve throughout the decades. Although providing an extensive overview of the many definitions of creativity is beyond the scope of this article, some understanding of the main principles of and perspectives on creativity is necessary.
In an attempt to provide a conceptualized definition of creativity, Theresa M. Amabile (1983) suggested three perspectives from which creativity can be regarded: creativity as a process (Wallas, 1926) (Hadamard, 1949), the creative person (Guilford, 1950) (Kirton, 1987), and the creative product (Besemer and Treffinger, 1981) (Besemer and O’Quin, 1986).
cognitive approach to understanding creativity entails understanding the underlying processes, mental representations, and mechanisms that lead to creativity.
Many academics believe J.P. Guilford’s 1949 Presidential Address to the American Psychological Association to be the starting point of serious cognitive, empirical work on the topic of creativity. Up to that point, creative ability was commonly believed to depend only on intelligence. Any research on intelligence was therefore believed to naturally apply to creativity as well. J.P. Guilford was among the first to challenge this common understanding by stating that other cognitive properties, rather than just intelligence, play an important role in determining creative ability of an individual as well. As a response, Guilford proposed a distinction between divergent and convergent thinking. He thereby paved the way for a wide variety of research on the connection between creativity and cognition, ranging from connections between creative problem solving and basic cognitive processes shared by all humans (such as attention, perception, memory, and information processing) to connections with intelligence, problem solving, language and other cognitive dimensions along which individuals can differ.
Runco (2007) presents several arguments to why using a cognitive perspective on creativity can be advantageous. One is based on the strong connection between cognition and creativity, found in many prior studies. Another major advantage of taking a cognitive approach to creativity is that cognitive research is often very scientific, which means studying the cognitive bases for creative problem solving can be done in “reasonably valid and reliable ways, in a controlled laboratory setting or with paper-and-pencil tests” (Runco, 2007).
Individual and small-group creative performance
Temperamental qualities refer to a person's general emotional disposition: his optimism, his moodiness, his self-confidence, or his nervousness for example (Guilford,1950).
Guilford’s insights are much in line with Amabile’s thoughts, who is one of the most prominent and important researchers on individual and small group creative performance in organizations. Figure 1 already showed how Amabile proposed a strong relationship between organizational innovation and individual and small group idea generation. In the same article, Amabile zooms in on idea generation by linking a revised version of her 1983 model of individual or small group creativity to the overall process of organizational innovation (see figure 2)(Amabile,1988). In essence, Amabile (1983) suggests three components to explain individual or small group creative performance; domain-relevant skills, creativity-relevant skills, and intrinsic task motivation. The three components are incorporated into a schematic representation of the overall process of individual creativity (see figure 2), consisting of five stages: task presentation, preparation, idea generation, idea validation, and outcome assessment. Each of the three components of creative performance has an influence on one or two stages of the process of individual or small group creativity (Amabile, 1988).
Accordingly, domain-relevant skills are the basis of any performance and include factual knowledge, technical skills, and special talents in the particular domain. Creativity-relevant skills however, can turn a particular performance from technically good or acceptable into a creative performance. Finally, intrinsic task-motivation deals with an individual’s motivation to perform an activity (Amabile, 1983)(Amabile,1988) and determines the extent to which “domain-relevant skills and creativity-relevant skills will be fully and appropriately engaged in the service of creative performance” (Amabile, 1988). Put differently, assuming an appropriate level of motivation to do the job is present, performance will be adequate or good when relevant domain-relevant skills exist, but it is the creativity-domain-relevant skills that can give the performance “something extra” (Amabile, 1983).
Note the strong overlap between Amabile’s intrinsic task motivation and Guilford’s motivational traits, as well as the strong resemblance between Guilford’s concept of creative ability and Amabile’s creativity-relevant skills. Both authors agree that other factors, together with creative skills, influence whether a person with creative abilities will actually produce a creative performance. This insight is important within the context of this thesis, as it provides a clear distinction between creative skills and creative performance, the first being a separate component of the latter.
Creativity-relevant skills (Skills in creative thinking)
Looking at figure 2, it becomes apparent that creativity-relevant skills (presented as “skills in creative thinking”), together with intrinsic task motivation, are of special importance at stage 3 of the process of individual or small group creativity, in which one or more ideas or products are being generated. Creativity-relevant skills influence the way in which the individual searches for solutions to the presented problem or task, in that they determine the amount of flexibility the individual uses in exploring cognitive pathways (Amabile, 1983)(Amabile, 1988). Sufficient intrinsic task motivation can add a willingness to take risks in finding solutions and notice aspects of the task that, at first sight, may not look obviously relevant to finding a solution.
In her article, Amabile (1988) frequently uses the terms ‘creativity-relevant skills’ and ‘skills in creative thinking’ to refer to the same concept. In order to avoid confusion, the term ‘skills in creative thinking’ shall be used in the remaining of this thesis.
Influence of physical exercise on skills in creative thinking
By adopting “skills in creative thinking” from Amabile’s theories, a concrete and specific way of dealing with the rather ambiguous concept of creativity has been established. This thesis will investigate the influence of physical exercise on employees’ skills in creative thinking. Following Amabile’s model (1988), improved skills in creative thinking may lead to improved individual and small-group creative performance, through enhanced idea generation. On its turn, the entire process of individual or small group creative performance forms the third stage in the overall process of organizational innovation. In sum, any increase in an individual’s skills in creative thinking, in this case due to chronic physical exercise, may very well indirectly benefit organizational innovation.
In the next paragraphs, a review of previous academic work on the influence of physical exercise on creativity will be presented. First, early work on the relationship between physical exercise and basic cognitive functioning is being reviewed to understand how physical exercise may influence processes in the human mind in general.
Influence of physical exercise on cognition
(Ramocki, 2002). An overview of this literature has great value within the context of this article, as it provides insights in ways that the relationship between physical exercise and general cognition has been studied before. Findings are useful for the remaining of this article, when scope narrows and emphasize is placed on creativity as a distinct cognitive skill.
Much of prior work on physical exercise and cognition has studied effects of physical arousal on cognitive tasks (Weingarten & Alexander, 1970) (Gutin, 1972) (Weingarten, 1973). First, Yerkes and Dodson’s (1908) inverted-U hypothesis predicts “that the current level of physical arousal will interact with an individual’s ability to perform psychomotor tasks” (Tomporowski & Ellis, 1986). As physical arousal increases, cognitive performance is expected to improve up to an optimal point and then deteriorates with further increases in physical arousal. Second, the drive-theory hypothesis, proposed by Spence & Spence (1966), suggests that an increase in physical arousal facilitates cognitive performance in a linear fashion. Both theories perceive physical arousal as a general state which can be influenced by factors such as anxiety, sleep deprivation, and physical exercise.
Although these studies provide some valuable insights in the relationship between physical exercise and cognition, their practical application is rather questionable. For example, if physical exercise would indeed facilitate cognitive abilities after physical exertion, this would imply that every time employees need to use their brain, managers need to let them do physical exercise first. Or, if physical exercise would impair mental functioning, should managers prohibit employees to participate in physical exercise prior to work?
This thesis is not concerned with mental performance during or directly after an acute bout of physical effort. It is concerned with the effects of systematic or chronic physical exercise on creative skills. In contrast to Tomporowski and Ellis (1986) and Tomporowski (2003), Etnier et al. (1997) provide a meta-analysis which also includes chronic exercise protocols and mixed acute and chronic exercise protocols. Etnier et al. (1997) point out that only two review articles have been dedicated to summarize results from studies using chronic training programmes. First, Folkins and Sime (1981) examined several studies on chronic exercise and psychological health, of which ten studies specifically dealt with chronic exercise and cognition. Most of these studies either emphasize on children, geriatric or geriatric mental patients. Only a study by Young (1979), which examined the link between regular fitness exercise and cognitive functioning and personality among healthy adults (24 -62 years old, both male and female), really provides relevance and value within the context of this thesis. Before and after a 10 week exercise programme, including jogging, callisthenics, and recreational activities, 32 subjects were assessed on functioning in a number of domains. Regardless of sex or age, significant improvements were observed at the end of the fitness programme on Digit Symbol Block Design, Trail-Making and Crossing-Off, as well as on Associate Learning (Young, 1979). These improvements “suggest improvements in perceptual psychomotor intelligence, neuropsychological function, psychomotor speed, and associate learning”(Young, 1979). No control group was used however, which led Folkings and Sime (1981) to rightly point out the pre-experimental research design of Young’s study as an important limitation to his findings. Pre-experimental designs fail to control various threats to internal validity adequately (Cooper & Schindler, 2006)
two out of three memory tests. According to Hughes (1984) the positive results of this study are important “because they represent one of the few times that exercise has been shown to improve objective measures of mental state in a clinical population”(Hughes, 1984). Obviously, generalization to normal adults, and therefore the relevance of this study within the context of this article, is in question here.
A more relevant study was conducted by Blomquist and Danner (1987), who tried to determine whether improvement in physical fitness of healthy adults is related to improvement in mental, information-processing efficiency. The study included pre testing and post testing (before and after 10-12 weeks) on four cognitive and information-processing tests and a bicycle test to estimate physical fitness. After the post test, subjects were divided into two groups based on their increase in VO2max (predicted maximum oxygen uptake) from pre test to post test: a Stable Group (no improve or improve of less then 5%) and an Improved Group (improvement of 15%). Subjects who improved 5 to 15% were eliminated from analyses. Eventually, some support was found for a relationship between physical fitness and information-processing efficiency, but improvements were not dramatic. The authors point out that “improvements in mental efficiency might have been larger if subjects had been less fit at pre test or had participated in a more vigorous fitness program (Blomquist & Danner, 1987). These suggestions may be quite relevant and important for the research design of this thesis.
Influence of physical exercise on creativity
Blanchette et al. (2005) conducted a similar study based on an acute bout of physical exercise. The study investigates the immediate and residual (2 hours after exercise) effects of aerobic exercise on creative potential, measured through the use of Figural Tests A and B of the Torrance Tests of Creative Thinking (Torrance, 1966). Two out of three hypotheses were strongly supported. First, participants demonstrated greater creative potential immediately after completing aerobic exercise than when they did not engage in aerobic exercise. Secondly, when the participants waited 2 hours after participating in an aerobic exercise, they still demonstrated higher scores, relative to not engaging in aerobic exercise session. Although not strongly, the third hypothesis was supported as well: “when the participants were tested immediately after an aerobic exercise session, they would not demonstrate significant different levels of creative potential than when they were tested 2 hr after completing an aerobic exercise session” (Blanchette et al., 2005). The authors conclude that these results represent “the strongest possible outcome in terms of supporting both immediate and residual effects of aerobic exercise on creative potential”(Blanchette et al., 2005). Acute bouts of aerobic exercise had significant effect on the creative potential of the participants, and these impacts were proven to endure over a 2 hour period. As is the case with the study of Steinberg et al. (1997), main implication of this research is once again the lack of pre testing. Also, as Blanchette et al. (2005) honestly point out their selves, the narrow range of ages of the participants adds to the limitations of this study as well.
measures. Mean change for fluency and novelty achieved high significance. However, although the article states that “results for the unfit control group clearly indicate that creativity levels failed to increase relative to the treatment group” (Ramocki, 2002), the majority of the measures did not achieve significance. Major implication of this study is again its pre-experimental design. Although Ramocki managed to incorporate pre and post measurement with treatment and control groups into the experimental design, the participants could not be randomly assigned to the experimental and control groups, because of the requirement that the treatment group had to be in top shape. As a result, Ramocki (2002) concludes that the study does strongly hint to vigorous exercise enhancing creativity, but that additional testing is necessary before this assumption can be ascertained.
As is the case with prior work on acute bouts of physical exercise and cognition, the studies presented above have similar practical implications for managers and organizations. Would physical exercise indeed facilitate creative thinking after physical exertion, should managers organize physical exercise sessions every time employees need to come up with creative output? Especially in companies or departments where creative output is demanded from employees almost continuously (R&D department, marketing etc.), this seems highly impractical. Instead, it would be much more interesting to see how chronic physical exercise, through long-term effects such as increased general health, might influence people’s overall capacity in creative thinking.
To sum up, there seems to be a general consensus among the academics discussed above to at least strongly assume the existence of a relationship between physical exercise and creativity. The studies using acute bouts of physical exercise (Steinberg, 1997)(Ramocki, 2002) (Blanchette et al., 2005) were accompanied by a questionable practical value however. Instead, this thesis will try and explore further the work of Gondola and Tuckman (1985), analyzing the influence of a chronic (systematic) programme of physical exercise on individuals’ skills in creative thinking. As a result, the first hypothesis to be tested in this study reads:
Hypothesis 1a: Respondents who participated in a chronic physical exercise program will demonstrate increases in measured skills in creative thinking from pretest to posttest.
A second conclusion is that none of the prior studies discussed above, managed to provide a true experimental research design. In this thesis, an attempt will be made to construct and administer a true experimental research design, consisting of pre and post measurement and a randomly assigned experimental and control group.
Hypothesis 1b: Respondents who participated in a chronic physical exercise programme will demonstrate higher increases in measured skills in creative thinking from pre test to post test, relative to respondents who did not participate in a chronic physical exercise programme.
Despite absence of a true experimental research design, Steinberg (1997) did make an effort to add other variables to the equation. Eventually, he found exercise to enhance creativity independently of changes in mood. However, as was stated before, Steinberg (1997) used acute bouts of exercise as manipulation. It would be interesting to see whether the same conclusion can be drawn when using a chronic exercise programme. The following hypotheses will be tested:
Hypothesis 2a: Respondents who participated in a chronic physical exercise programme will experience increases in positive mood.
Hypothesis 2c: Improvements on measured skills in creative thinking of respondents who participated in a chronic physical exercise programme could be explained by increases in positive mood.
Hypothesis 2d: Improvements on measured skills in creative thinking of respondents who participated in a chronic physical exercise programme could be explained by decreases in negative mood.
Finally, by studying whether physically fit individuals would perform better on various measures of creativity relative to non-physically fit individuals, Ramocki (2002) made an attempt to incorporate the level of individual physical fitness to the proposed relationship. Instead of comparing physically fit and non-physically fit individuals, it would be very interesting to see whether following a chronic exercise programme enhances an individual’s level of physical fitness and, subsequently, lead to improvements in measured skills in creative thinking. According to the US department of health and human services (2008), only a few weeks of participation in physical activity can result in achieving health benefits such as increased cardio respiratory fitness (usually expressed as VO2max, estimated maximal oxygen uptake), increased muscular strength, and decreased depressive symptoms and blood pressure (US department of health and human services, 2008). As a result, the following hypotheses will be tested as well:
Hypothesis 3a: following a programme of chronic exercise enhances a respondent’s individual level of physical fitness.
Hypothesis 3b: experimental group’s improvements on measured skills in creative thinking could be explained by increases in respondents’ level of individual physical fitness.
CONCEPTUAL MODELS
creativity-relevant skills, through improved idea generation, may lead to improved overall individual and small-group creative performance, which on its turn forms the third stage in the overall process of organizational innovation (see figure 2). These subsequent steps in Amabile’s model are beyond the scope of this research however. As the blue box indicates, emphasis in this research is on the influence of chronic physical exercise on an individual’s skills in creative thinking.
Figure 3 Conceptual model 1
Figure 4 Conceptual model 2:
Figure 5 Conceptual model 3:
Individual physical fitness as a moderator variable
Dependent variable: Skills in creative thinking
Independent variables Chronic physical exercise
A broad variety of physical exercise activities and programs have been used in prior research on the subject. Within this thesis, the US department of health and human services guidelines to an active lifestyle shall be used (US department of health and human services, 2008). Accordingly, respondents need to participate in a 60-minute-workout twice a week during a month. Workouts will consist of 40 minutes of cardiovascular workout (cross trainer, jogging and cycling) and 20 minutes of strength training (strength training equipment and lifting weights).
Individual physical fitness
Due to the complex physiology of a human body, an individual’s level of physical fitness is a complex variable as well. Measurement can be done in many ways and can include a broad range of physiological aspects like blood pressure, cardio respiratory fitness, muscular strength, muscular tension, glucoses, fat percentage etc. In this thesis, a selected range of relatively simple tests on physical fitness will be conducted. The same tests are used by general practioners, fitness professionals, and health counsellors.
Mood
Similar to a human’s physique, a human’s psyche is very complex as well. As a result, measuring mood can be a very complicated process. For the sake of practicality and due to a lack of sufficient knowledge about a human’s brain and emotions, mood shall be measured using self-reports of positive and negative mood adjectives.
METHODOLOGY
In order to construct a true experimental design, randomly assigned experimental and control groups needed to be formed. From several Dutch companies, employees were invited to take part in this study. Important condition for selection was that the respondent was, at the time, exercising less than once a week. Eventually, 30 employees were selected and randomly assigned to either the experimental group or control group, which both consisted of 15 employees each. Importantly, for the sake of limiting response biases, respondents were not told specifically that the study they were going to participate in dealt with creativity.
minutes of strength training, consistent with the US department of health and human services guidelines to an active lifestyle. Workouts were organized in groups of 1-4 participants at a time. Scheduling of the workouts was flexible to avoid interference with the participants’ work and all physical exercise sessions were monitored by a certified fitness instructor. No incentive pays were given to the participants. In return for their participation, the employees were granted free access to the luxurious fitness club at which this research was facilitated.
Participants from both groups were pre-tested and post- tested on physical fitness, mood and skills in creative thinking. First, participants were asked to rate their own physical fitness on a scale from 1 to 10. Next, testing of cardio respiratory fitness (using the Ästrand-test on an indoor cycle, which estimates the maximal oxygen uptake of individuals), blood pressure, fat percentage, heart rate in rest, and heart rate after 5 minutes of physical activity took place.
The moderator variable ‘mood’ was measured using a mood-adjective list, based on the one used by Steinberg (1997), containing ten positive and ten negative adjectives (see appendix C). On a 5-point scale respondents needed to score the extent to which each adjective reflected their mood at that time. Also, two simple questions were asked to assess concentration and productivity, in order to keep the real subject of the study, skills in creative thinking, hid.
‘Elaboration’ (a number of ideas added beyond the minimum details that would be necessary for the basic response). Finally, output of the TTCT-Figural activity ‘repeated figures’ was scored on ‘Fluency’, ‘Originality’, and ‘Abstractness of titles’. Differently from the TTCT-Verbal activity ‘unusual uses’, every single response on ‘repeated figures’ was scored on ‘Originality’ and ‘Abstractness of title’. Final rating of an individual respondent on these two measures was constructed by calculating the mean of all of his/her relevant drawings.
Internal validity of the research design
The research design described above is a Pretest-Posttest Control Group Design (Cooper & Schindler, 2006). As a result, many internal validity problems are dealt with rather adequately, although some difficulties still exist. First, considerable threat of dropouts is present, as not all of the participants in the experimental group may succeed in completing all of the workouts. Flexible scheduling of the workout sessions solved this problem to a certain degree. Also, dropouts may occur in the control group, as participants start to participate in physical exercise more regularly themselves, triggered by their bad scores on the physical fitness tests. Solution to this problem was to not disclose the individual’s score before the end of the experiment.
Secondly, a testing threat to internal validity may be present as the experience of taking the pre-test can have a learning effect that influences the results of the post-pre-test (Cooper & Schindler, 2006). The proposed usage of different stimulus for pre and post-test and the time interval of one month in between pre and post-test provided a solution to this problem.
External validity of the research design
A Pretest-Posttest Control Group Design can hold several threats to external validity (Cooper & Schindler, 2006). Main threat in this research comes from interaction of selection, as participants need to agree to participate (self-selection). In the case of self-selection, generalization to the total population (other employees) is questionable (Cooper & Schindler, 2006). Other threats to external validity, like reactivity of testing or other reactive factors, were less likely to occur in this research.
Measurement tool: The Torrance Test for Creative Thinking
with the TTCT-Verbal. The TTCT-Figural has not been used that much however. This research uses both parts of the Torrance Tests of Creative Thinking. Main reason is the general criticism on using paper-and-pencil tests to assess creativity. According to Sternberg and Lubart (1996), paper-and-pencil tests, like the ones used in the TTCT-Verbal, are too trivial and more significant productions such as drawings need to be used in addition. Additionally, Cropley (2002) suggests that, seeing the multidimensionality of creativity, assessment of creativity should be based on several tests, rather than relying on a single one.
Validity
The validity, the extent to which a measurement tool measures what the researcher actually wishes to measure (Cooper & Schindler, 2006), of the TTCT is very high. Main reason for choosing the TTCT to measure the dependent variable ‘skills in creative thinking’ is that it claims to measure “creative thinking abilities”, which are defined as intellectual abilities that are used in creative achievements (Torrance, 1990). Interestingly, it is explicitly mentioned that the TTCT does not measure motivation, skill, or any other of the components that may influence an individual’s ultimate creative performance (Torrance, 1990)(Kim, 2006). This is very much in line with Amabile’s (1983) theories on creative performance, distinguishing “skills in creative thinking” as just one of the three components necessary for creative performance. It is not surprising therefore, that there is a strong overlap between the TTCT-scoring components and the several specific cognitive-perceptual aspects that were found to characterize persons with skills in creative thinking (Amabile, 1983)(Amabile, 1988). Suspension of judgment, for example, shows strong resemblance with the TTCT-Figural scoring component ‘resistance to premature closure’. Similarly, exploring new cognitive pathways seems very much related to TTCT-scoring component ‘originality’, while ‘using a broad range of categories in storing information’ exhibits strong overlap with scoring-component ‘Flexibility’, which refers to the variety of ideas generated.
Reliability
Practicality
Finally, the Torrance Test for Creative Thinking scores high on the criteria practicality. It is easy to administer and the standardized nature of the TTCT makes interpreting fairly easy.
RESULTS
After exercising twice a week during a month, the initial experimental group of fifteen people was down to twelve. Unfortunately, three respondents dropped out half-way. Also, only twelve out of fifteen respondents from the control group managed to show up for the post-tests. Luckily, dropouts were evenly distributed among both groups, resulting in both a final experimental and control group of twelve respondents. Sex of the respondents was evenly distributed among both groups as well (see figure 6). Although ideally the samples would be bigger, there were still enough respondents to draw statistical inference from.
Several techniques of statistical testing were used, including the paired samples test, Wilcoxon Signed Ranks Tests, Mann-Whitney U tests, Spearman rank correlation, and simple linear regression (Keller, 2005). Results were considered highly significant when the p-value was less than 0.01, and considered significant when the value lay between 0.01 and 0.05. When the p-value exceeded 0.05, results were considered not statistically significant.
M=male F=female * E=exp.group C=contr.group Crosstabulation Count E=exp.group C=contr.group C E Total M 6 6 12 V 6 6 12 M=male F=female Total 12 12 24
Figure 6 Distribution of respondents
Chronic physical exercise and skills in creative thinking
Paired samples tests were used to compare the experimental group’s pre-performance and post-performance on the different TTCT tests (see figure 7). Improvements were found on ‘Fluency’ on task 2, ‘Fluency’ on task 4, ‘Abstractness of title’ on task 4, and ‘Elaboration’ on task 3. The improvement on the measure of ‘Fluency’ on task 4 between PRE and POST was highly significant (t=-3,452, p=0,0025). In other words, overwhelming evidence was found to infer that the experimental group’s ‘Fluency’ scores on task 4 had improved between PRE and POST (p<0,01). Furthermore, no improvements were found on ‘Flexibility’ on task 2. Respondents even scored worse on “Originality” on task 4, but this finding was not statistically significant.
Paired Samples Test
Paired Differences 95% Confidence Interval of the Difference Mean Std. Deviation Std. Error
Mean Lower Upper t df
Sig. (2-tailed) Pair 1 Fluency_tk2_PRE - Fluency_tk2_POST -1,250 3,388 ,978 -3,403 ,903 -1,278 11 ,228 Pair 2 Fluency_tk4_PRE - Fluency_tk4_POST -5,417 5,435 1,569 -8,870 -1,964E0 -3,452 11 ,005 Pair 3 Origi_tk4_PRE - Origi_tk4_POST ,18792 ,47991 ,13854 -,11700 ,49284 1,356 11 ,202 Pair 4 Flex_tk2_PRE - Flex_tk2_POST ,000 2,449 ,707 -1,556 1,556 ,000 11 1,000 Pair 5 Ab.title_tk4_PRE - Ab.title_tk4_POST -,003833 ,305555 ,088206 -,197974 ,190307 -,043 11 ,966 Pair 6 Elab._tk3_PRE - Elab._tk3_POST -,417 2,234 ,645 -1,836 1,003 -,646 11 ,532
Figure 7 Results of paired samples test: comparison
of pre- and post scores on the various measures of creativity on the different tasks
on ‘Originality’ on task 3 and ‘Abstractness of title’ on task 3, with the latter even being significant (Z=-1,983, p=0,0235).
So, although improvements were found on five TTCT measures, only one improvement of performance was highly significant. As a result, it is only fair to conclude that not enough evidence was found to accept hypothesis 1a.
Mean pre - and post-scores of experimental group on creativity measure 'fluency' on task 4
14,25 19,75 0 5 10 15 20 25
Fluency task 4 PRE Fluency task 4 POST
Figure 8 Mean scores on pre-and post-
measurement of creativity measure ‘Fluency’ on task 4. The difference is statistically significant (p=0,0025) Test Statisticsc Origi_tk2_POST - Origi_tk2_PRE Origi_tk3_POST - Origi_tk3_PRE Ab.title_tk3_POS T - Ab.title_tk3_PRE Z -,816a -1,613b -1,983b Asymp. Sig. (2-tailed) ,414 ,107 ,047
a. Based on negative ranks. b. Based on positive ranks. c. Wilcoxon Signed Ranks Test
Hypothesis 1b: Respondents who participated in a chronic physical exercise programme will demonstrate higher increases in measured skills in creative thinking from pre test to post test relative to respondents who did not participate in a chronic physical exercise programme.
First, the same paired samples test was applied to the control group (see Appendix C, figure 2). Similar to the experimental group, there were increases found on ‘Fluency’ on task 4, ‘Originality’ on task 4, ‘Abstractness of title’ on task 4, and ‘Elaboration’ on task 3. None of these improvements were even close to significance however. Respondents even scored worse on post-testing of ‘Fluency’ on task 2, and ‘Flexibility’ on task 2, with the latter achieving statistical significance (t=2,462, p=0,016). For the ordinal variables, the same Wilcoxon Signed Ranks Tests were applied to the control group (see Appendix C, figure 3). No improvements were found on any of the tasks and creativity measures. On the contrary, respondents from the control group scored worse on post-testing of ‘Originality’on task 2 and 3, and ‘Abstractness of title’ on task 3. None of these findings were significant though.
Figure 10 Results of Independent samples test: comparing
difference in pre and post- performance on ‘Fluency’ on task 4
between experimental and control group Independent Samples Test
Levene's Test for
Equality of Variances t-test for Equality of Means
95% Confidence Interval of the Difference
F Sig. t df
Sig.
(2-tailed) Mean Difference
Std. Error
Difference Lower Upper
Equal variances
assumed ,585 ,453 2,419 22 ,024 5,00000 2,06675 ,71382 9,28618 DifFluency4
Equal variances not
assumed 2,419 21,500 ,024 5,00000 2,06675 ,70803 9,29197
Independent Samples Test
Levene's Test for Equality
of Variances t-test for Equality of Means
95% Confidence Interval of the Difference
F Sig. t df Sig. (2-tailed)
Mean Difference
Std. Error
Difference Lower Upper
Equal variances assumed ,018 ,895 1,607 22 ,122 1,50000 ,93339 -,43573 3,43573 DifFlex2
Equal variances not
Interestingly, a highly significant difference was found on ‘Fluency’ on task 4 (t=2,419, p=0,012) (see figure 10). In other words, the experimental group’s improvement of performance on ‘Fluency on task 4’ was found to be significantly higher, relative to the control group.
There was also some evidence of the experimental group outperforming the control group on ‘Flexibility’ on task 2(t=1,607, p=0,061). Main reason however, was a decline in pre-to post-performance within the control group. Furthermore, the control group had improved post-performance more on ‘Originality’ on task 4 (t=-1,511, p=0,0725)(see figure 11) while the Mann-Whitney U tests pointed to the control group outperforming the experimental group on ‘Abstractness of title’ on task 3 (Z=-1,413, p=0,079). None of these findings were significant though. Eventually, similar to hypothesis 1a, not enough evidence was found to accept hypothesis 1b.
Mood and skills in creative thinking
Hypothesis 2a: Respondents who participated in a chronic physical exercise programme will experience increases of positive mood
Hypothesis 2b: Respondents who participated in a chronic physical exercise programme will experience decreases of negative mood.
Using a paired samples test, the experimental group’s pre-and post total positive and negative mood adjectives were compared. From the statistical testing results, presented in figure 12, it becomes apparent that strong evidence was found to infer that positive mood increased (t=-2,334, p= 0,021) and negative mood declined (t=2,400, p=0,0175) after following a chronic exercise program. Both findings are significant (both 0,01<p<0,05), resulting in acceptance of hypotheses 2a and 2b.
Paired Samples Test
Paired Differences 95% Confidence Interval of the Difference Mean Std. Deviation Std. Error
Mean Lower Upper t df
Sig. (2-tailed) Pair 1 Mood.pos.PRE - Mood.pos.POST -2,909 4,134 1,246 -5,686 -,132 -2,334 10 ,042 Pair 2 Mood.neg.PRE - Mood.neg.POST 3,750 5,413 1,562 ,311 7,189 2,400 11 ,035
Figure 12 Results of Paired samples test: comparing differences in
Hypothesis 2c: Improvements on measured skills in creative thinking of respondents who participated in a chronic physical exercise programme could be explained by increases in positive mood.
In order to study a possible relationship between improved positive mood and improved performance on measured skills in creative thinking, linear regression analysis was conducted. Decision was made to only conduct regression analysis for the measures of creativity that were found to have significantly improved from pre – to post test. This resulted in ‘Fluency’ on task 4 being the only creativity variable in the regression analysis.
Figure 13 shows that no significant linear relationship was found (F=0,083, p=0,388). As a result, no evidence was found to support hypothesis 2c.
ANOVAb
Model Sum of Squares df Mean Square F Sig. Regression 2,694 1 2,694 ,083 ,776a Residual 711,139 22 32,324
1
Total 713,833 23 a. Predictors: (Constant), DifMoodPos
b. Dependent Variable: DifFluency4
Coefficientsa
Unstandardized Coefficients
Standardized Coefficients
Model B Std. Error Beta t Sig. (Constant) 3,133 1,381 2,269 ,033 1
DifMoodPos -,076 ,264 -,061 -,289 ,776 a. Dependent Variable: DifFluency4
Figure 13 Results of regression analysis on
Hypothesis 2d: Improvements on measured skills in creative thinking of respondents who participated in a chronic physical exercise programme could be explained by decreases in negative mood.
Similar analysis was conducted for negative mood. No significant evidence was found for a linear relationship between improvement in performance on ‘Fluency’ on task 4 and decreases in negative mood either (F=0,094, p=0,3825). As a result, hypothesis 2d was rejected.
ANOVAb
Model Sum of Squares df Mean Square F Sig. Regression 3,030 1 3,030 ,094 ,765a Residual 321,886 10 32,189
1
Total 324,917 11 a. Predictors: (Constant), DifMoodNeg
b. Dependent Variable: DifFluency4
Coefficientsa
Unstandardized Coefficients
Standardized Coefficients
Model B Std. Error Beta t Sig. (Constant) 5,053 2,022 2,499 ,031 1
DifMoodNeg -,097 ,316 -,097 -,307 ,765 a. Dependent Variable: DifFluency4
Figure 14 Results of regression analysis on
‘difference in negative mood’ and ‘Fluency’ on task 4.
Level of individual physical fitness
exercise programme, respondents from the experimental group rated their own physical fitness an average of +1 higher compared to the pre-testing, while respondents from the control group rated an average of +0.17 higher. Main disadvantage of course, is the questionable objectivity of this measure. Eventually, it was decided to use the measures ‘Self-assessment of physical fitness’, ‘Maximum oxygen uptake’, and ‘Heart rate after 5 minutes of physical activity’.
Hypothesis 3a: following a programme of chronic exercise enhances a respondents’ individual level of physical fitness.
A Wilcoxon Signed Ranks test was used to compare differences in experimental group respondents’ scores on various tests of physical fitness between pre- and post-test. First, there was overwhelming statistical evidence to infer that following a programme of chronic exercise enhances a respondent’s self-assessment of individual physical fitness. This finding was highly significant (Z=-2,585, p=0,005).
Test Statisticsb
Subj.wb.POST - Subj.wb.PRE Z -2,585a Asymp. Sig. (2-tailed) ,010
a. Based on negative ranks. b. Wilcoxon Signed Ranks Test
Figure 15 Results of Wilcoxon Signed Ranks test: comparison of differences on
respondent’s ‘Self-assessment of individual physical fitness’.
With maximum oxygen uptake’, ‘heart rate after 5 minutes of activity’, and ‘Fluency’ on task 4 all being ratio data, a paired samples test was conducted to make a similar comparison between pre and post. From the statistical testing results listed in figure 16, it becomes clear that weak statistical evidence was found to infer that ‘maximum oxygen uptake’ (t=-1,482, p=0,083) and ‘heart rate after 5 minutes of activity’ (t=1,707, p=0,058) were improved due to following a chronic exercise programme. In the case of ‘heart rate after 5 minutes of activity’ a lower heart rate indicates better stamina.
Figure 16 Results of Paired Samples test on ‘Maximum oxygen uptake’
and ‘Heart rate after 5 min. of activity’.
Hypothesis 3b: experimental group’s improvements on measured skills in creative thinking could be explained by increases in respondents’ level of individual physical fitness.
New variables were formed by calculating all pre- to post-test differences on the physical fitness measures for the experimental group. Similar to the analysis of the relationship between mood and performance on measured skills in creative thinking, regression analysis was conducted for the three measures of individual physical fitness. For ‘Self-assessment of physical fitness’, conducting a Spearman rank analysis resulted in a lack of evidence for a linear relationship (p=0,390)(figure 17). Regression analysis did not result in finding significant relationships for ‘Maximum oxygen uptake’ and ‘Heart rate after 5 minutes of activity’ either (see figures 18 and 19). Therefore, hypothesis 3b was rejected.
Correlations DifSelfAss DifFluency4 Correlation Coefficient 1,000 ,090 Sig. (1-tailed) . ,390 DifSelfAss N 12 12 Correlation Coefficient ,090 1,000 Sig. (1-tailed) ,390 . Spearman's rho DifFluency4 N 12 12
Figure 17 Results of Spearman rank test for ‘Self-assessment
of physical fitness’ and ‘Fluency on task 4’
Paired Samples Test
Paired Differences 95% Confidence Interval of the Difference Mean Std. Deviation Std. Error
Mean Lower Upper t df
Coefficientsa
Unstandardized Coefficients
Standardized Coefficients
Model B Std. Error Beta t Sig. (Constant) 5,818 1,775 3,277 ,008 1
DifVO2max -,892 1,609 -,173 -,554 ,592 a. Dependent Variable: DifFluency4
Figure 18 Results of regression analysis for
‘Maximum oxygen uptake’ and ‘Fluency on task 4’.
Coefficientsa
Unstandardized Coefficients
Standardized Coefficients
Model B Std. Error Beta t Sig. (Constant) 4,997 1,828 2,734 ,021 1
DifHfAct -,103 ,205 -,157 -,502 ,627 a. Dependent Variable: DifFluency4
Figure 19 Results of regression analysis for ‘Heart
rate after 5 minutes of physical activity’ and ‘Fluency on task 4’
CONCLUSION AND DISCUSSION
as well, relative to respondents from the control group (t=2,419, p=0,012). Task 4 consisted of two pages of repeated figures, which respondents had to use as stimulus to make as much drawings as possible. As was already proposed in the methodology section, the measure of ‘Fluency’ refers to the recording of the number of relevant responses and, on this task, thus reflected the respondent’s ability to produce a number of figural images (Kim, 2006). The results show that the respondents who participated in a chronic physical exercise programme managed to produce significantly more drawings during task 4, relative to the respondents who did not exercise. The fact that the respondents from the experimental group made more drawings, does provide evidence of the positive effects of physical exercise on individuals’ skills in creative thinking. It is interesting to see that performance had improved specifically on a TTCT-Figural task. Several researchers have criticized brief paper-and-pencil tests (like the ‘Unusual uses’ task) and, instead, identify more significant productions like drawings as more adequate measures of creativity (Sternberg and Lubart, 1996)(Hocevar & Bachelor, 1989). Respondents not only have to think of a response, they also have to express their thoughts through producing figural images. The task “repeated figures” captures the multidimensionality of creativity (Torrance, 1990) and the finding of improved performance on this particular task is therefore quite useful. Furthermore, ‘Fluency’ is the most objective measure of all TTCT measures, as it is recorded simply as the number of relevant responses. Rater biases are therefore less likely to occur, contrary to the more subjective measures of ‘Originality’ or ‘Abstractness of title’. This adds value to the finding as well. Finally, the findings are much in line with Ramocki (2002), who found significant differences and mean changes on the particular measure of ‘Fluency’ as well.
seemed, had improved independently of increased physical fitness or improved mood. Regarding mood, these results are much in line with the findings of Steinberg (1997).
Regardless of influence on creativity, the findings on mood and physical fitness itself are quite valuable to managers. It is not hard to imagine that the happiness of an employee can positively contribute to a company’s working atmosphere or influence an employee’s job motivation or willingness to cooperate with colleagues. Furthermore, many studies have shown the economic benefits of healthier employees, mainly through decreases in employees’ absence through sickness and improvements in productivity (US department of health and human services, 2008).
One could state that this study failed to discover a clear relationship between physical exercise and skills in creative thinking. Indeed, overwhelming statistical evidence was found for only one measure of creativity on only one creative task. However, none of the prior studies on the subject managed to identify significant changes or differences on more than two measures of creativity either. It did not keep those researchers from at least strongly assuming the existence of a relationship between physical exercise and creativity. If anything, the significant improvement on ‘Fluency’ on task 4, together with the identified improvements that were not significant, only confirms this assumption. In other words, similar to prior research on the subject, this thesis at least hints to physical exercise enhancing creativity, and makes apparent that further research is still necessary before this assumption can be ascertained. Most importantly, by providing a first attempt to conduct a true experimental research on the subject of physical exercise and creativity, this thesis provides several very important and interesting guidelines for future research.
LIMITATIONS
Several limitations of this research are important to place the findings mentioned above into the right perspective. First of all, relatively small samples were used. Both the experimental and control group eventually consisted of 12 people. It was found difficult to motivate people to participate in the study and, secondly, to keep them from dropping-out.
program should be a serious consideration for any further research. On the other hand, this would probably mean that keeping respondents motivated becomes even harder.
Another important limitation is the difference in time at which the respondents were tested before and after the chronic exercise program. Ideally, every respondent would be pre – and post tested at the exact same time, but in practice this proved to be an impossible task. For example, some people that were pre-tested on a free day were post-tested in the evening, coming in after a long day’s work. Very likely, this particularly influenced the results on heart rate at rest and blood pressure. This situation occurred mainly with respondents from the experimental group, resulting in similar or even worse scores on the post-tests of blood pressure and heart rate in rest.
Post-testing respondents after a long days work could also very well influence mood and performance on the different creativity tasks. Although solving this problem is difficult, future research would benefit when serious attention is given to making sure respondents are pre- and post tested at approximately the same time.
The lack of a second (or even third or fourth) scorer of the TTCT output also holds an important limitation to this research. Although a serious effort was made to find more judges, only one academic agreed to lend his assistance. Maybe a bigger incentive pay would have solved this problem.
A final limitation may be found in the fact that no official TTCT scoring manual was used to score the respondents’ output of the Torrance Test of Creative Thinking. Because no funds were available for this research, buying a scoring manual was to costly. In this study, the different TTCT measures were used separately. Within the official TTCT scoring guide, all measures are summed up to form a composite score, resulting in an overall assessment of an individual’s creative skills. When sufficient funds are available, buying and using official TTCT tests and scoring manuals would definitely be beneficial to further research.
DIRECTIONS FOR FURTHER RESEARCH
Next to learning from the limitations, several other directions for further research can be subtracted from this research. For example, in this study, separate aspects of individual physical fitness were used. In further research it would be interesting to combine multiple aspects of individual physical fitness into one general variable to measure an individual’s overall level of physical fitness. Usage of medical software can be of great value here.
