Vice or virtue? How interacting with nature influences self-control.

Vice or virtue?

How interacting with nature influences self-control.

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Vice or virtue?

How interacting with nature influences self-control.

University of Groningen

Faculty of Business and Economics Msc Marketing Management Master Thesis

June 2015

Supervisor: Dr. Yannick Joye

2nd supervisor: Prof. Dr. Bob M. Fennis

Laura Wittek

Witte de Withstraat 8a 9726 EC Groningen

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Abstract

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Preface

“The value of achievement lies in the achieving”. This quote by Albert Einstein perfectly describes what I feel when finally being granted the academic title ‘Master of Science in Marketing’. This academic title, of course, sounds nice and I am more than proud of myself, to have arrived at this point. But what makes this academic title valuable is the journey, how we students got there. Ten months of studying at the Rijksuniversiteit Groningen. A time full of new experiences, perspectives and last but not least challenges.

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Table of content

2.1 The benefits of nature on human well-being ... 4

2.1.1 Enhanced positive emotions ... 5

2.1.2 Stress reduction ... 5

2.1.3 Restored attention – Basic idea ... 6

2.2 The construct of attention restoration ... 7

2.2.1 Attention Restoration Theory ... 7

2.2.2 Restorative qualities of environments ... 8

2.2.3 Existing studies on ART ... 9

2.3 Modality and length of exposure to nature ... 10

2.4 Ability to self-control ... 11

2.5 Vice and Virtue products ... 12

2.6 Conceptual model ... 13

2.6.1 Effects on the ability to self-control ... 14

2.6.2 Attention restoration ... 16 3. Methodology ... 17 3.1 Research Design ... 17 3.2 Participants ... 17 3.3 Materials ... 18 3.3.1 Stimuli ... 18 3.3.2 Depletion Manipulation ... 19

3.3.3 Measures and their reliability ... 19

3.3.4 Procedure ... 21

4. Results ... 23

4.1 Preliminary analysis ... 23

4.2 The influence of depletion level and environment on self-control ... 23

4.3 The influence of depletion level and environment on attention restoration ... 25

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5. Discussion ... 28

5.1 Main effects of depletion level and environment on self-control ... 28

5.2 The role of attention restoration ... 29

6. Managerial Implications ... 31

7. Limitations and further research ... 32

References ... 34

Appendices ... 39

Appendix A: Two-way ANOVA - The influence of depletion level and environment on self-control ... 40

Appendix B: Post Hoc Test – Comparison of means of self-control across conditions ... 41

Appendix C: Two-way ANOVA - The influence of depletion level and environment on attention restoration ... 42

Appendix D: Post Hoc Test – Comparison of means of attention restoration across conditions ... 43

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1. Introduction

Modern life in urban environments is characterized by an excessive number of stimuli and overload of information (Han, 2003). First of all, demands at the workplace have increased and individuals are forced to concentrate in order not to be distracted and prevent errors in performance. Besides that, a popular example for this development is the advertising clutter for an ever growing amount of products that compete for our attention (Pieters, Warlop and Wedel, 2002). To resist buying products promoted in-store or in TV commercials, self-control is needed to make good and well-considered choices and decisions (Baumeister et al., 1998).

Due to advanced technology shop-at-home television programs or internet shopping channels exist, that make consumers able to buy and consume immediately and most notably around the clock (Vohs and Faber, 2007). Resisting offerings by exerting self-control is becoming more and more difficult as the occasions at which self-control is challenged increase. This is based on the fact that self-control is said to depend on a limited resource that can be depleted by overuse (Kaplan and Berman, 2010). It is a specific type of attention, which is also demanded by the various stimuli of everyday life as for example advertising. A lot of unimportant things capture an individuals’ attention that could otherwise help it to have greater control over itself. The consequences of the lack of the ability to focus attention on important issues, are self-control failures like impulse buying (Vohs and Faber, 2007), or the consumption of fattening food (Hanif et al., 2012).

In the case of the consumption of unhealthy products, attention is moved away from the long-term goal of healthy eating and instead, directed towards the immediate situation and potential pleasure (Baumeister and Heatherton, 1996) of a food that is fat, but tasty. Literature makes a distinction between products that are likely to be bought under self-control (virtue products) and products that are bought as a result of self-control failure (vice products, Ein-Gar, 2012). For example it needs much more self-control to not buy a tasty bar of chocolate that could give the consumer immediate pleasure, than not buying an apple that would contribute to the persons’ health in the long-run.

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This research will investigate one possible answer to this question. It will take a deeper dive into the role of nature, referred to as “any single element of the natural environment (such as plants, animals, soil, water or air)” (Maller et al., 2005, p. 46), in supporting the consumption of healthy products.

In general the existing academic literature provides a large number of research studies, in which nature is found to have a positive effect on human well-being (Velarde, Fry and Tveit, 2007). This effect is not found to the same extent for urban environments as they are lacking specific characteristics like peacefulness for example (Bratman, Hamilton and Daily, 2012) and rather are the source of attention being depleted by overwhelming stimuli.

While the link between nature and self-control could perhaps feel surprising, there is actually research showing that nature can have a positive influence on self-control, or on its specific antecedents. Interacting with nature is said to, amongst other things, restore depleted attention, which is discussed in the Attention Restoration Theory (Kaplan, 1995). As attention is found to be a necessity to exert self-control (Kaplan and Berman, 2010), nature can probably enhance an individuals’ control over the self. This in turn would be reflected in a healthier lifestyle due to the increased ability to resist unhealthy products and therefore make more prudent choices. This leads to the following research question:

What is the effect of exposure to natural scenery on self-control with regard to preferences for vice or virtue products?

In order to understand these relationships in more detail, this research will focus on three main variables that may have effects on each other: the ability to exert self-control, the type of environment an individual is exposed to, and the level of depleted attention. The following three effects will be researched:

1. The effect of exposure to natural or urban environments on self-control measured by product preferences. A distinction is made between preference for virtue and vice products.

2. The effect of participants’ attention being subject to different levels of depletion before measuring the ability to self-control.

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2. Literature Review

To begin, the general benefits of nature on human well-being are discussed, and three important strands of literature are briefly introduced. The focus is specifically put on one of the main theories on the human-nature relation, namely the restoration of attention, which is further linked to the construct of self-control. This literature review is aimed at giving a sound theoretical understanding of both, the constructs and variables involved in the current research. Besides that, it will serve as the starting point for the developed hypotheses. Thus a proposition for the conceptual model and the derivation of the corresponding hypotheses based on existing literature will follow the literature review.

2.1 The benefits of nature on human well-being

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also revealed, when imagery like slides or photographs (Ulrich, 1981) depicting natural scenery were used in several laboratory studies. Researchers have observed three important positive effects, nature has on the overall well-being of humans: enhanced positive mood, stress reduction and recharged attention (White et al., 2003).

2.1.1 Enhanced positive emotions

The first of the three most important benefits, nature has on the well-being of humans, are enhanced positive emotional states (Ulrich et al., 1991). By referring to this finding of Roger Ulrich et al. (1991), Ke-Tsung Han (2003, p. 211) in specific describes that such positive emotions embrace “positive feelings such as pleasure, happiness, satisfaction, and tranquility”. Previous literature has shown that interacting with nature in different forms in fact increases feelings of happiness and at the same time reduce negative feelings such as fear or anger (Ulrich et al., 1991; Van den Berg, Koole and van der Wulp, 2003). In addition Thomas R. Herzog and Kristi K. Chernick (2000) asked participants of their study to rate color slides showing both, urban and field/forest natural settings on different aspects. Whereas participants experienced a feeling of tranquility and security with natural settings, slides depicting urban settings evoked a feeling of danger rather than tranquility.

2.1.2 Stress reduction

When looking at the existing research, restoration is a major concept frequently discussed when the benefits, nature can have on human well-being are investigated. The Oxford English Dictionary describes restoration as “the action of restoring a person to health or consciousness” (Han, 2003, p. 211). Three authors have extensively concentrated on the effects of nature on restoration. Whereas Roger Ulrich (and colleagues)viewed restoration as being derived by the calming effect of nature that blocks feelings of stress, Stephen Kaplan and Rachel Kaplan (1989) claimed that the restorative effect is due to a replenished attentional capacity (Hartig, Mang and Evans, 1991; Bratman, Hamilton and Daily, 2012).

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the individuals’ “unconscious, autonomic response to natural elements” makes up their healing power (Ulrich, 1993 cited in Bratman, Hamilton and Daily, 2012, p. 122). To give an example, Hartig et al. (2003) found, that after participants had to perform a test of attentional performance, interaction with nature decreased the level of blood pressure of the participants, which is an indication of reduced stress. Furthermore, an increase in positive affect through a decrease in feelings of anger and aggression was observed in this same study. As the evolution of human-beings took largely place in natural environments, these natural settings automatically transfer a feeling of safety to us and thereby reduce feelings of stress (Ulrich et al., 1991). According to Roger Ulrich, nature with water elements or vegetation especially evoke positive affection among humans. This is based on the fact that such places were qualified for the survival of our species, as resources like food had been spotted quickly and helped them survive.

2.1.3 Restored attention – Basic idea

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2.2 The construct of attention restoration

People engage in a lot of activities in their daily lives that ask for their mind to focus on something. The most obvious occasions, where this is expected, are at the workplace or for example at the university, places, where one has to use attentional resources. The longer one has to pay attention, the harder it gets to stay focused on the important and suppress any distraction. This state of mind is referred to as “mental fatigue” (Kaplan, 1995). Possible and obvious means to overcome this fatigue could be sleep or meditation (Kaplan, 2001). At first glance it seems that they are effective, but both have their drawbacks (Kaplan and Berman, 2010). The amount of sleep our body can put up with is limited and individuals wake up before their attention is fully restored. Meditation, in contrast, needs knowledge, skill and patience to work effectively, which makes this means not accessible for everyone. A third intervention mentioned by Marc G. Berman, John Jonides and Stephen Kaplan (2008) to improve cognitive performance is the consumption of glucose. As paying attention towards an object or task lowers the level of glucose in the blood, the consumption of the latter re-establishes the ability to direct attention (Gailliot et al., 2007). Besides the presented means, it was already introduced that attention can also be restored by experiencing nature.

2.2.1 Attention Restoration Theory

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Inspired by the writings of William James, Stephen Kaplan calls these attentional mechanisms ‘directed attention’ (voluntary attention) and ‘fascination’ (involuntary attention) (Berto, 2005). As one can see, there are different terms used for the two types of attention. However, they are all based on the same underlying phenomenon: there exist stimuli that we automatically attend to, and objects we specifically have to direct our attention to.

It was Frederick L. Olmsted (1865, cited in Kaplan, 1995), a landscape architect, who believed that this capacity to focus can be fatigued. Based on that, ART claims that the capacity of control that has to be exerted to direct attention, becomes fatigued, whereas fascination is resistant to this (Kaplan and Talbot, 1983; Kaplan and Kaplan, 1989 cited in Hartig, Mang and Evans, 1991). Any continuing mental effort depletes directed attention. This state of mind negatively influences our actions, thoughts and feelings. Individuals might for example experience a feeling of irritation, a lack of concentration that increases the likelihood of making errors or are unable to make proper plans (Korpela and Hartig, 1996; Tennessen and Cimbrich, 1995). Thus directed attention is necessary for us to be effective. ART states that, when an individual is in a mode of fascination, it allows directed attention to rest and replenish (Berto, 2005). Thereby a moderate level of fascination, just enough to effortlessly focus attention, is necessary.

People are inherently fascinated by certain stimuli that they effortlessly draw attention to (Bratman, Hamilton and Daily, 2012). When talking about fascination, Stephen Kaplan (1995) distinguished between two different types. On the one hand, there is ‘soft’ fascination, which could be triggered by a nice walk through nature. On the other hand, there is ‘hard’ fascination like watching a car race. If one compares both types, it is soft fascination, which is provided by interacting with nature and that can lead to restoration. Frederick L. Olmsted (1865, cited by Kaplan, 1995) perfectly described the restorative role of nature by stating that it “employs the mind without fatigue and yet exercises it; tranquilizes it and yet enlivens it; and thus, through the influence of the mind over the body, gives the effect of refreshing rest and reinvigoration to the whole system” (p. 174).

2.2.2 Restorative qualities of environments

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to which an individual can escape from daily life and mental routines. By getting away from the concerns and content of urban life individuals are able to avoid using directed attention (Herzog, Maguire and Nebel, 2003). Furthermore, environments should be “of substantial scope” to provide ways to experience and explore it (Extent, Hartig et al., 2003, p. 110). If content and structure of the environment are sufficient to occupy an individuals’ mind, this allows directed attention to have a rest (Herzog, Maguire and Nebel, 2003). Lastly an individuals’ purposes and inclinations should match with the environment (compatibility). If environments support the performance of intended activities and being oneself, it is easier for an individual to function and therefore economize on directed attention. Whereas other environments might score high in some of the four dimensions, all of them are most consistently and simultaneously satisfied by natural environments. Especially ordinary natural environments such as “back yards, gardens, nature trails, field/forest settings“ (Herzog, Chen and Primeau, 2002, p. 295) prove to be rich in qualities, necessary to provide restorative experiences, as humans are innately fascinated by them. Overall, this expected restoration ability of natural over urban scenery, makes individuals prefer them as favorite place (Staats Kieviet and Hartig, 2003; Hartmann and Apaolaza-Ibanez, 2010).

2.2.3 Existing studies on ART

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Recent research by Patrick Hartmann, Vanessa Apaolaza and Patxi Alija (2013) was the first to apply the theoretical framework of ART to advertising. Within three studies they tested the impact of pleasant natural scenery in advertisements on the processing of the advertisements’ message. In the end both, recognition and recall of the message, could be improved through greater directed attention towards this message. The work shows that the benefits, nature has on an individual, can be useful and important aspects for marketers and their advertising tactics.

2.3 Modality and length of exposure to nature

When investigating the impact of natural environments on human well-being, different types of exposure have been applied throughout the stream of literature. People, who have been part of different experiments, have been exposed to nature by images, window views or actually being physically present outdoors (Bratman, Hamilton and Daily, 2012). Mathew P. White et al. (2013) investigated the influence of nature visits on restoration and found a positive relationship with length of the stay. In their review, Mahdieh Abkar

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and Gretchen C. Daily (2012), were distributed according to type of exposure (y-axis) and duration of exposure (x-axis). Moreover, it illustrates that previous studies mainly investigated either “the impacts of different living conditions’ access to nature” (p. 130, Lifetime) or experimental designs that exposed individuals for a period between “10 min and an hour” (Bratman, Hamilton and Daily, 2012, p. 13). In general it makes sense that studies, using images to represent nature, are very low in duration due to the fact that people will not be motivated to look at them for hours. In conclusion, nature seems to influence the health of people regardless of the modality of exposure.

2.4 Ability to self-control

By now it was shown, that human beings can benefit from exposure to nature in many ways, with attention restoration being the focus of the present work. But the chain of effects does not stop here. Emerging literature suggests that attentional mechanisms are related to the concept of self-control (e.g., Baumeister and Heatherton, 1996; Rueda, Posner and Rothbart, 2005). The individuals’ ability to direct attention is said to be a necessity in performing self-control (Kaplan and Berman, 2010).

In general, self-control can be performed in three forms (Taylor, Kuo and Sullivan, 2002). Firstly self-control is needed to delay gratification. For this, an individual must overcome preferences for immediate pleasure and appreciate long-term rewards. Second, self-control has to be exercised to concentrate and prevent the mind from wandering about. And lastly it is necessary to inhibit impulses and be able to consider other alternative courses of action, to be better able to make prudent choices. In all three cases the way, an individual would feel, think or behave, changes by performing self-control (Muraven and Baumeister, 2000). A good example, provided in the work of Stephen Kaplan and Marc G. Berman (2010), shows that, whereas an individual might have the inclination to eat very unhealthy but delicious food (impulse), he or she would resist to do so in order to keep up his or her intended diet (goal behavior). As in the case of directed attention, the strength of self-control is as well termed a ‘resource’. This infers that it “is finite in quantity and depleted by heavy demands” (Kaplan and Berman, 2010, p. 43). The more often the self has to exert control over itself, the more this resource gets depleted.

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against impulses to buy. The results of their first experiment showed that participants, whose self-control resources were depleted, were willing to pay more. It turned out that they attached more value to the goods and therefore perceived them to become expensive at a higher point. Additionally, a second experiment revealed that the number of goods bought, and the amount of money spent by participants of the resource depletion condition, was higher compared to the control condition. Depleted participants also “felt more tempted than non-resource-depleted participants” (Vohs and Faber, 2007, p. 541). These findings underline that resources, to exert self-control, are finite and undergo depletion.

Besides this depletion, conflicts between goals and standards (for example feel good immediately versus save money) or the failure of an individual to monitor its behavior undermine self-control (Baumeister, 2002). Although the capacity for self-control is limited, it nonetheless can be recovered. This is, when directed attention comes into play, as its manipulation can enhance this capacity. That attention benefits “subsequent self-regulation by maximizing the mental resources that remain available for such acts” (p. 109), was shown in the work of Asma Hanif et al. (2012). This simply means that individuals, who effectively allocate attention, prevent that this resource is used for irrelevant activities. Thus, attentional mechanisms can enhance self-control by facilitating that information, relevant for achieving a goal, can be processed and unfavorable responses inhibited. This is in line with the finding of Stephen Kaplan and Marc G. Berman (2010), that decreasing the amount of attention demanding stimuli, environments expose individuals to, would enhance self-control.

2.5 Vice and Virtue products

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the point of decision, but on the other hand contribute to less negative outcomes in the long-run and are therefore often attributed to be the more well-considered choice. Therefore, literature speaks of "wants" and "shoulds", when referring to vice and virtue products (Van Doorn and Verhoef, 2011). Examples of virtue (healthy) products are dental floss, gym workouts, sunscreen lotion, car seatbelts and condoms (Ein-Gar et al., 2012). Although not very related to immediate pleasure, they prevent us from getting sun-burn, unwanted pregnancy, gain weight or getting hurt in a car accident, which are future benefits associated with the products. Tobacco, alcohol (Lee and Callcott, 1994) or chocolate cake (van Doorn and Verhoef, 2011) are typical examples of vice (unhealthy) products, we often want, rather than need to buy. In the case of the chocolate cake its delicious taste is confronted with its downturn of gaining weight in the future.

How exactly self-control can be linked to the preference or choice of virtue (healthy) in comparison to vice (unhealthy) products, will be shown in the discussion of the conceptual model.

2.6 Conceptual model

14 Figure 2 Conceptual Model1

Researchers investigated the effect of different types of environments on human well-being a lot (see collection of studies in Bratman, Hamilton and Daily, 2012). Thereby, environments were either broadly categorized into urban and nature settings or more specifically different subcategories of nature, like for example scenery enriched with forest, field or water elements, have been compared (Bratman, Hamilton and Daily, 2012). Among the different subcategories of nature, water seems to play the most important role. Its attention holding features as well as its ability to transmit a feeling of tranquility, make it especially restorative (Ulrich, 1981). For the sake of this research, the broad distinction between urban and natural environments will be of interest. Since the effects of nature on an individual further were found to hold across all types of exposures, whether it be a visit, image or window view (Bratman, Hamilton and Daily, 2012), it makes the exposure of participants to environments in form of a video justifiable. In the following, the relationships, depicted in the conceptual model, are discussed in more detail.

2.6.1 Effects on the ability to self-control

A delay of gratification requires an individual to give up immediate gratification for remote payoffs in the long-term (Baumeister and Heatherton, 1996). Based on the discussed literature it is known that virtue products are less gratifying at the point of decision, than vice products,

1 _{The original model included exposure time as a third independent variable. It was manipulated by showing videos}

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but provide gratification in some future point in time. Delaying gratification is an act of control. This leads to the conclusion that for preferring a virtue over a vice product some self-control is needed, in order to focus on long-term payoffs (Baumeister and Heatherton, 1996). A high level of directed attention thereby enhances self-control (Kaplan and Berman, 2010). As depleted individuals are lacking attentional capacity, they are expected to prefer the unhealthy food option. Based on this, the following hypotheses can be derived:

H1: The higher the level of depletion, the lower the ability to self-control.

Self-control is dependent on attentional capacities, which are likely to be enhanced by natural instead of urban environments. So far, attentional restoration has been mostly investigated to take place as a consequence of exposure to nature in a state of depletion. The current study expands this finding by analyzing the effect of nature separately from the level of depletion. Besides the expected effect of nature in a depletion condition, it is also expected to positively influence restoration, when the individual is non-depleted. Although there is no need for restoration, nature can still be vitalizing in a way that it provides an experience that gives one a feeling of new mental energy (Ryan et al., 2010). This could enhance restoration and therefore self-control.

H2: Exposure to natural scenery increases the ability to self-control more than exposure to urban scenery.

As already pointed out in the literature review, natural environments are leading the list of favorite places due to their high expected restorative effects on depleted attention (Staats, Kieviet and Hartig et al., 2003; Hartmann and Apaolaza-Ibanez, 2010). A visit in nature seems to recover attention and thus increases an individuals’ strength in controlling itself. The latter effect gives rise to the belief that nature, compared to urban environments, can have a bigger effect on healthier product choice in the depletion condition. So an interaction between depletion level and type of environment is expected. The following hypothesis will be tested:

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The relationship of restoration, depletion and exposure to natural environments has been discussed in detail and supported by several researchers (for example Hartig, Mang and Evans, 1991; Tennessen and Cimprich, 1995). As nature is rich in characteristics that catch attention without any effort, directed attention can rest and be replenished. This is far less the case for urban environments. Additionally, as highlighted in the context of self-control, a vitalizing effect of nature on non-depleted individuals can be expected to take place. The exposure to nature is therefore nevertheless restorative in a way.

H4: Exposure to nature increases attention restoration more than exposure to urban scenery.

It is furthermore interesting to see, whether the level of depletion has an effect on restoration, independently of the environmental condition. Restoration is described as the procedure of “entering a situation in which functioning does not involve demand on directed attention” (Hartig et al., 1997, p. 176). The opposite is true for individuals that completed an effortful cognitive task that demanded attention. Therefore, it is reasonable to expect that they will feel less restored. Individuals, who are in a non-depleted mental state, will feel more restored as their minds are still fresh and able to direct attention.

H5: The higher the level of depletion, the lower the restoration.

The mechanism of directed attention is an essential ingredient for the self, to be able to alter behavior, thoughts and feelings in order to control each of them (Muraven and Baumeister, 2000). A healthy product choice necessitates self-control. That again is driven by attention and attentional capacities are highest, when restoration is high. An individual that perceives his/her attentional resources to be rested, will be able to perform well. Therefore, someone, whose attention is not depleted (anymore) but refreshed, will be able to control him-/herself and choose the more healthy option.

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3. Methodology

Important literature has been summarized and several hypotheses as well as the appropriate conceptual model were introduced in the previous chapter. Empirical research was conducted, to test the established hypotheses embedded in the conceptual model. The following chapter will elaborate on the methodology of this research. This incorporates the discussion of the research design and participants as well as the used materials including manipulations, measurements and the procedure of the online experiment.

3.1 Research Design

To assess the above established hypotheses, the conceptual model was empirically tested with a two-group factorial design. Quantitative data was obtained by means of an online experiment that was designed in the research platform Qualtrics. In the experiment manipulation was achieved through two different cognitive tasks participants had to do and by varying between two different videos participants had to watch. Thus, the current research was comprised of a 2 by 2 between-subjects design with ability to self-control as the dependent variable, and

depletion level (non-depletion vs. depletion) and environmental condition (nature vs. urban) as

the independent between-subject variables. Each participant was randomly assigned to one environmental condition and one depletion condition. Conditions were assigned evenly across all participants.

3.2 Participants

After two weeks of data gathering a final set of 239 respondents of the online survey was generated. Responses of 73 participants (31%) had to be excluded as their responses were incomplete, what made 166 participants in total. Of these 166 participants 64 (38.6%) were male and 102 (61.4%) were female. The age among participants ranged from 16 to 68 years (Mage = 24.52, SD = 4.97). Overall participants were rather young, which was probably due to

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Furthermore, as the questionnaire was provided in English, participants from different countries were invited to take part in the survey.

3.3 Materials

3.3.1 Stimuli

The stimuli used within the scope of this study were two self-made videos, each showing a specific environment. The two videos depicted either a natural or an urban environment in color (see Figure 3.1 for sample movie shots of the nature condition and Figure 3.2 for sample movie shots of the urban condition). The nature video was shot in Groningen, whereas the urban video was shot in Münster (Germany).

Figure 3.1 Movie shots of the nature condition

Figure 3.2 Movie shots of the urban condition

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Daily, 2012). Furthermore, no such elements like a rainbow, sunset or thunderstorm were shown, which are typical elements of awesome, exceptional nature (Keltner and Haidt, 2003). The nature used in this study can rather be categorized as mundane. Mundane nature depicts nature that can be seen in everyday life, such as trees, a river, a cow and farm land. In contrast, the urban condition showed everyday life in cities that stands for a dense population, busy streets and urban noise (Han, 2003).

Due to a rather low resolution of the video, participants were not able to maximize its size to full screen as thereby the quality of the video would have suffered. Since it was important that participants watched the full length of the video, this was ensured by removing the possibility of fast-forwarding it. To enhance the imagination of the participants, the sounds of the videos were turned on.

3.3.2 Depletion Manipulation

In order to differentiate between the effects on self-control in different states of depletion, the manipulation of the latter was necessary. Therefore, participants were randomly assigned to a cognitive task on one of two levels. One level, that should mentally fatigue participants and an easy level that should not require much effort. In the depletion condition, participants were asked to retype a short text, but leave out the letter “e”. As this requires a certain amount of attention to successfully perform this task, participants were expected to be depleted. In the non-depletion condition, participants only had to retype two short sentences without any extra rules, which should require less effort. The sentences included rational information about management practices, in order to prevent any influence on the emotions of the participants.

3.3.3 Measures and their reliability

Mood measurement. To measure baseline mood at the start of the survey, a mood measurement

was taken. Participants had to indicate the mood they were in at that moment, using a sliding scale that ranged from 0 (the worst I have ever felt) to 100 (the best I have ever felt; scale taken from Sherman Haidt and Coan, 2009). On average, participants were in a better than average mood when starting to fill in the survey (Mmood = 64.24, SD = 17.24), what held for both, male

(Mmood = 63.85, SD = 18.18) and female (Mmood = 64.49, SD = 16.71) participants. The measured

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Attention Restoration. After participants had watched one of the two videos, the restorative

qualities of the environment shown in this video were measured. For that, the Perceived Restoration Scale (PRS, scale taken from Hartig et al., 1997) was used. It consists of 16 items that are grouped according to the four dimensions of restorative qualities: Being away, Fascination, Extent and Compatibility. The participants had to state, to which extent the given statements fit the environment they experienced by watching the video. They had to do so on a 7-point Likert scale (1 = not at all, 7 = completely). “It was a confusing place” (extent) or “I can do things I like here” (compatibility) are two exemplary statements participants had to rate. As it is important to check the reliability of the constructs that were used, Cronbach’s Alpha was calculated to measure internal consistency. A scale is reliable, when it produces consistent results across repeated measurements (Malhotra, 2010). A Cronbach’s Alpha larger than or equal to 0.6 confirms internal consistency, what means that the items, included in the scale, measure the same construct. The PRS, consisting of the 16 items, was proven to be reliable as Cronbach’s Alpha was 0.832 and therefore exceeded the critical value by far. Furthermore all subscales - Being away (2 items, 0.850), Fascination (5 items, 0.896), Extent (4 items, 0.883) as well as Compatibility (5 items, 0.914) - showed a sufficient Cronbach’s Alpha with regard to their number of items, to conclude that they are reliable.

Product preference. In the end of the survey the ability to self-control was measured.

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Figure 4 Exemplary product pair displaying a virtue product on the left and a vice product on the right 3.3.4 Procedure

An online questionnaire that included self-reporting measures was created, as the internet is an appropriate channel to obtain data from participants. Fast and easy distribution of an online link to the questionnaire via Facebook or e-mail, as well as the availability of digital data that facilitate the processing of the results (Malhotra, 2010), are advantageous features of this method. Additionally, snowballing (ask people you contact directly to forward the link to their family and friends) can be used to increase the reach of the questionnaire.

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4. Results

4.1 Preliminary analysis

So far, participants, who did not complete the survey, have already been deleted from the data set. To further clean the data set, an outlier analysis on the dependent variable (ranging from 1 to 7) was conducted. Outlier detection calculations based on the mean and standard deviation (M ± 3SD) as well as a box plot showed that there were no outliers for ability to self-control. No further participants had to be deleted, due to their numerically distance to the remaining data.

To reveal systematic differences between the participants assigned to the four experimental conditions, with regard to the demographic variables gender and age as well as the variable

mood, appropriate tests have been conducted. A one-way ANOVA was used to investigate if

the metric variables have a significant influence in differentiating the four groups. As age and

mood are both metric variables, a one-way ANOVA was conducted. Condit was placed as the

factor, whereas age and mood were the dependent variables that were tested. Significance was based on the ratio of the between-group variance compared to the within-group variance expressed by the F value (Malhotra, 2010). A variable shows substantial significance, when the alpha is lower than 0.05 for a confidence interval of 95%. The results of this analysis showed that for both, mood, F(3, 162) = 1.18, p = .319 and age, F(3, 162) = 1.17, p = .324, none of the criteria

that show statistical significance are fulfilled, which means that the experimental conditions do not systematically differentiate in mood and age. Therefore, changes in the dependent variable,

ability to self-control, cannot be attributed to those two variables.

As only significant differences based on metric variables have been tested, cross tabulation is now used that gives a joint frequency distribution of the non-metric variable gender among the conditions. To see if there exists a significant relationship between conditions and gende,r a Chi-square test was conducted. An alpha of 0.551 that is larger than 0.05 showed that there is no systematic difference between the values of gender for each experimental condition.

4.2 The influence of depletion level and environment on self-control

24

was conducted. Environmental condition (nature versus urban) and depletion level (depleted versus non-depleted) were the between-subject variables, and time since last meal the covariate. This covariate was included, because the fact that the last meal was some hours ago, could have made participants less able to resist unhealthy food.

The results of the two-way ANOVA (Appendix A) revealed if there were statistically significant interactions between environmental condition, depletion level and ability to

self-control. Again, a variable showed substantial significance, when the alpha was lower than 0.05

for a confidence interval of 95%. Both main effects, environmental condition on ability to

self-control, F(1, 161) = 1.36, p = .245 and depletion level on ability to self-control, F(1, 161) = 3.51, p

= .063, were statistically not significant. Therefore, Hypotheses 1 and 2 that depletion and nature increase the ability to self-control were not supported. Additionally, no interaction between environmental condition and depletion level, F(1, 161) = .52, p = .473 was found, so

Hypothesis 3 was also not confirmed. Finally, the covariate time since last meal had no statistically significant effect on ability to self-control, F(1, 161) = 1.39, p = .247.

Although the effects were statistically not significant, with Figure 6 some more insights into the direction of the effects could be gained. First of all it shows that in general participants, who were primed with the nature video, chose the healthier product by scoring lower on the product preference scale, Mself-control = 3.60, SD = 1.21, and therefore showed higher self-control,

compared to participants primed with the urban video, Mself-control = 3.84, SD = 1.51. Moreover

participants in the depletion condition, on average, scored a little higher on ability to

self-control, Mself-control = 3.50, SD = 1.25, than participants in the non-depletion condition, Mself-control

= 3.90, SD = 1.45, as they were closer to 1, which represented the healthy product choice. The graph visualizes the finding of the two-way ANOVA that there is no interaction between the two independent variables, environmental condition and depletion level, since they are not crossing each other. Moreover Figure 6 shows the biggest difference in the ability to self-control between the nature/depletion and urban/non-depletion condition. This difference in the ability

to self-control between these two conditions was also found significant in a post hoc test, p =

.040. (Appendix B). Furthermore, based on the post hoc test, a marginal significant difference in the ability to self-control between urban/depletion and urban/non-depletion condition exists,

25

Figure 6 Effects of depletion level and environmental condition on self-control

So far it was tested if there is a direct relationship between the independent variables,

environmental condition and depletion level on ability to self-control. Since this was not the

case, it is now interesting to examine the effects of the video manipulation on attention

restoration. As pointed out in the literature review, a relationship between environmental condition and attention restoration, between depletion level and restoration as well as between attention restoration and ability to self-control is likely to exist. This is examined in the

following paragraphs.

4.3 The influence of depletion level and environment on attention restoration

The relationships between depletion level and attention restoration as well as environmental

condition and restoration are important. They could bridge the connection between ability to self-control and the latter two independent variables, since attention restoration is expected to

be a driver of the ability to self-control. If nature or a low level of depletion increase attention

restoration (H4 and H5) and attention restoration is expected to enhance the ability to self-control (H6), some important relationships could be supported. Within the online questionnaire

26

that gave insights into the relationships between attention restoration, environmental condition and depletion level (Appendix C). While environmental condition and depletion level were used as independent variables again, this time attention restoration was the dependent variable. The main effects analysis revealed that both, environmental condition, F(1, 161) = 52.14, p = .000

and depletion level, F(1, 161) = 6.74, p = .010, significantly influenced attention restoration.

However, the two-way interaction between the independent variables was statistically not significant, F(1, 161) = 1.33, p = .251.

From Figure 7 the direction of the effects could be concluded. First of all one could see that for participants in the nature condition average attention restoration scores were higher, Mrestoration

= 3.58, SD = .95, than for participants in the urban condition, Mrestoration = 2.65, SD = .67. This

led to the acceptance of Hypotheses 4, which stated that exposure to nature increases restoration more than exposure to urban scenery. Furthermore, attention restoration scores were also higher for participants, who have not been depleted, Mrestoration = 3.27, SD = 1.01, than for

participants, who have been depleted, Mrestoration = 2.90, SD = .80. Therefore, Hypothesis 5,

which claimed that a higher level of depletion leads to lower restoration, was supported. As the independent variables do not cross each other, this confirmed that there was no interaction between them.

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Figure 7 Effects of depletion level and environmental condition on attention restoration

4.4 Correlation analysis between attention restoration and self-control

By now it was shown that environmental condition as well as depletion level have a significant influence on attention restoration. To take this a step further, it was investigated, what happened with ability to self-control, when attention restoration went up. This was done by a bivariate correlation analysis (Appendix E). When looking at the results, it could be concluded that there was a moderate negative correlation, r = -.170, p = .028, between attention restoration and ability to control. This means that, when restoration was higher, scores on the control scale decreased. As the healthy product anchored 1, this means that the ability to

self-control increased. Hypothesis 6, which claimed that restoration enhances self-self-control, was

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5. Discussion

In most research on human-nature interactions, relatively little attention has been dedicated to the effect, nature can have on consumption behavior. The current research aimed at testing, whether nature that is considered to have a positive impact on the human well-being, also has a positive influence on product choices. If nature can, in fact, stimulate healthy consumption behavior, it could be an important means to reduce or impede obesity, which was introduced as one of the severe outcomes of uncontrolled consumption, society is currently facing. Although self-control, but not attention restoration, was the main outcome variable of the current research, attention restoration still plays a major role, being considered as an important antecedent of the ability to self-control (Kaplan and Berman, 2010). Different levels of self-control strength, in turn, led to different product choice behaviors. Whereas no direct effect of nature on the ability to self-control was found, the current study came up with a chain of effects triggered by exposure to nature that led to higher self-control. These findings are further elaborated on in this chapter.

5.1 Main effects of depletion level and environment on self-control

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and recommend “circumspection about the existence of this phenomenon” (p. 1). They mention a possible overestimation of the effect within existing literature due to publication bias. With regard to this, an effect of depletion through its manipulation might be hard or even impossible to obtain.

The current study is one of the first to relate interacting with nature to the choice of unhealthy versus healthy products. It was hypothesized that nature will increase the ability to self-control due to its attention enhancing qualities (Herzog, Chen and Primeau, 2002). This relationship was found to be statistically not significant. However, it was revealed within the current study and will be elaborated in the following chapter, that nature can be an important indirect driver of enhanced self-control.

Based on the literature on attention restoration (Kaplan, 1995), it was furthermore reasonable to expect that the effect of depleted attention on self-control would be especially diminished in combination with exposure to a natural environment. This is what Jason T. Chow and Shun Lau (2015, p.70) recently evidenced: exposure to natural environments mitigates “the negative impacts of ego-depletion”. Based on the analysis of the interaction effect between type of environment and depletion level that showed no statistical significance, the respective hypothesis was rejected. This might be a consequence of attentional depletion being difficult to manipulate, according to some recent research of Evan C. Carter and Michael E. McCullough (2014).

5.2 The role of attention restoration

Although there was no direct effect of nature on self-control, in the found study it was found that nature led to increased attention restoration, and that attention restoration in turn led to higher self-control. Nature was able to provide restorative experiences that, in turn, refreshed attentional capacity and therefore enhanced the ability to self-control. Aside from that, a state of non-depletion was associated with high attention restoration. These findings are elaborated in the following, starting by the exploration of the effect of depletion level on attention restoration.

30

restoration to be significantly higher, than depleted individuals, due to a possible feeling of being in a good mental state or higher mental freshness.

Ordinary nature, as shown in the video of the nature condition within this study, is assumed to have restorative qualities (Herzog, Chen and Primeau, 2002). This was why a positive effect on attention restoration was expected, and indeed also found. Participants exposed to the nature video, reported higher restoration, than participants in the urban condition regardless of their level of depletion. Nature therefore positively affected the participants’ mental state in either case. This led to the conclusion that nature had positive effects on attentional resources, regardless of participants being in a state of depletion or non-depletion. This finding is not fully consistent with the Attention Restoration Theory (Kaplan, 1995), as also participants in a non-depletion state felt restored. Therefore, this effect can additionally be attributed to a vitalizing effect of nature (Ryan et al., 2010) in a non-depletion state, as hypothesized within the conceptual model. According to Richard M. Ryan et al. (2010, p. 159), “vitality is defined as having physical and mental energy”, which in fact positively influenced attention restoration. So overall, this study confirmed that nature with its fascinating elements like for example water, is able to catch one’s attention without it taking effort. Thereby, voluntary or directed attention that is needed to focus on tasks or objects, can rest and is refreshed, regardless of the manipulation of the state of depletion.

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6. Managerial Implications

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7. Limitations and further research

There are, of course, some limitations to the current study. A first one is, that people’s ability to self-control was measured by using a self-report scale. They had to decide between two products, a healthy (anchored 1) and an unhealthy choice (anchored 7). This is a common way of measuring preferences, but it can lead to response-bias, such as impression management and social desirability. These two biases refer to denying socially undesirable behaviors or traits, and to show socially desirable ones (Furnham, 1986). Therefore, it is likely that some participants chose the healthier option, since people don’t like seeing themselves as unhealthy or fast-food junkies. An idea would be, to let participants choose from actual food that they would be allowed to eat. So, instead of having plenty of time, when sitting at home in front of the computer, to decide between pictures of food, they could just grab the apple or cookie. This also makes the task more authentic. It would be a more intrinsic choice as people would not have time to think about, what reaction is most desired by society or the researcher.

Additionally, this study does not account for the participants’ food preferences. When the self-control measurement in the form of product choices was asked, food preferences in general could have biased the participants’ choice. Someone, who is on a strict diet or athletes, who eat very healthy for example, would probably have the tendency to choose the healthier product as a matter of principle. It could also be the case that someone never eats certain things, because s/he simply does not like the taste, which would also have influenced the food choice. Future research should therefore account for this, by simply asking about the participants’ general preference for each food that they will have to choose from, at the beginning of the survey. In the further analysis it could then be used as a control variable.

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Appendices

Appendix A: Two-way ANOVA - The influence of depletion level and environment on self-control

Appendix B: Post Hoc Test – Comparison of means of self-control across conditions

Appendix C: Two-way ANOVA - The influence of depletion level and environment on attention restoration

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Appendix A: Two-way ANOVA - The influence of depletion

level and environment on self-control

Source Type III Sum

of Squares

df Mean Square F Sig.

Corrected Model 12,797a 4 3,199 1,712 ,150

Intercept 1231,583 1 1231,583 659,062 ,000

Time since last meal 2,606 1 2,606 1,394 ,239

Environmental condition 2,546 1 2,546 1,362 ,245 Depletion level 6,558 1 6,558 3,509 ,063 Environmental condition * depletion level ,966 1 ,966 ,517 ,473 Error 300,859 161 1,869 Total 2616,531 166 Corrected Total 313,656 165

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Appendix B: Post Hoc Test – Comparison of means of

self-control across conditions

(I) conditions (J) conditions Mean

Difference (I-J)

Std. Error Sig. 95% Confidence Interval Lower Bound Upper Bound

natdep urbdep -,08130 ,31926 ,799 -,7117 ,5491 natnondep -,25630 ,30814 ,407 -,8648 ,3522 urbnondep -,64360* ,31100 ,040 -1,2577 -,0295 urbdep natdep ,08130 ,31926 ,799 -,5491 ,7117 natnondep -,17500 ,29443 ,553 -,7564 ,4064 urbnondep -,56230 ,29742 ,060 -1,1496 ,0250 natnondep natdep ,25630 ,30814 ,407 -,3522 ,8648 urbdep ,17500 ,29443 ,553 -,4064 ,7564 urbnondep -,38730 ,28545 ,177 -,9510 ,1764 urbnondep natdep ,64360* ,31100 ,040 ,0295 1,2577 urbdep ,56230 ,29742 ,060 -,0250 1,1496 natnondep ,38730 ,28545 ,177 -,1764 ,9510

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Appendix C: Two-way ANOVA - The influence of depletion

level and environment on attention restoration

Source Type III Sum

of Squares

df Mean Square F Sig.

Corrected Model 41,841a 4 10,460 16,156 ,000

Intercept 939,082 1 939,082 1450,446 ,000

Time since last meal ,481 1 ,481 ,742 ,390

Environmental condition 33,758 1 33,758 52,140 ,000 Depletion level 4,365 1 4,365 6,743 ,010 Environmental condition * depletion level ,858 1 ,858 1,326 ,251 Error 104,238 161 ,647 Total 1746,148 166 Corrected Total 146,080 165

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Appendix D: Post Hoc Test – Comparison of means of

attention restoration across conditions

(I) conditions (J) conditions Mean

Difference (I-J)

Std. Error Sig. 95% Confidence Interval Lower Bound Upper Bound

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Appendix E: Correlation analysis between attention

restoration and self-control

Restoration Self-control Restoration Pearson Correlation 1 -,170 * Sig. (2-tailed) ,028 N 166 166 Self-control Pearson Correlation -,170 * ₁ Sig. (2-tailed) ,028 N 166 166