Perceptions of gratitude

3

Behavioural Science Institute Master Science Thesis

Running head:

Perceptions of Gratitude

What a “Thank You� can do: Perceiving Gratitude facilitates Prosocial Behaviour toward Third Parties

Vera Rommeswinkel

Dr. Johan Karremans Prof. dr. Roos Vonk

21 JANUARI 2010

Supervised by:

Radboud University Nijmegen

Perceptions of Gratitude *

Abstract

The present research builds on an evolutionary model of gratitude, according to which gratitude functions to reinforce prosocial behaviour (McCullough, Kimeldorf, & Cohen, 2008).

To test this hypothesis, we conducted two studies in which we evoked prosocial behaviour of our participants upon which the beneficiary either expressed gratitude, or gave a material reward to the participant, or expressed acknowledgement of having received help (control condition).

The dependent variable was subsequent willingness to help a charity organization. We predicted and found that willingness to help was higher in the gratitude as compared to the reward condition. This result was replicated in Study 2. In addition, participants in the reward condition were less willing to help than participants in the control condition. As hypothesized, perceptions of the beneficiary’s gratitude mediated the effect of the gratitude versus reward condition. The results are discussed with regard to the evolutionary model of gratitude and in the light of theories about prosocial behaviour toward third parties (i.e., upstream reciprocity: Nowak & Roch, 2007). Suggestions for future research and implications for fundraising campaigns are presented.

Keywords:

Gratitude, Prosocial Behaviour, Reciprocity, Overjustification Effect

5

Perceptions of Gratitude *

What a “Thank You” can do: Perceiving Gratitude facilitates Prosocial Behaviour toward Third Parties

When learning a new language, “Thank you” is likely among the expressions people are most eager to learn.

Gratitude has been praised as “the parent of all other virtues” (Cicero, 1851, p. 139), its absence has been deemed “of all crimes [...] the most horrid and unnatural” (Hume, 1739, p. 20). Expressions of gratitude are ubiquitous in our everyday life, including the ‘virtual reality’ of the world wide web; one just needs to take a look at the comments on any popular video on the internet platform YouTube(c) to find hundreds of viewers expressing their gratitude.

Psychological research, however, has granted surprisingly little attention to the study of gratitude until the last decade. Since then, several studies have provided evidence for the determinants and consequences of gratitude on the part of the beneficiary (i.e., the person who has received help).

It has been shown that feeling grateful positively affects overall well-being (Emmons & McCullough, 2003; Algoe, Haidt, & Gable, 2008; Wood, Maltby, Gillett, Linley, & Joseph, 2008) and motivates prosocial behaviour of the beneficiary toward the benefactor (i.e. the person who has provided help) as well as toward third parties (Bartlett & DeSteno, 2006).

Not only the feeling of gratitude but also the perception of gratitude in another person, or being the target of gratitude, motivates prosocial behaviour. Perceiving an expression of gratitude has been demonstrated to reinforce prosocial behaviour of the benefactor toward the beneficiary (Rind & Bordia, 2006).

In light of recent theorizing about the adaptive functions of gratitude (McCullough, Kimeldorf, & Cohen, 2008), an interesting question is whether being the target of gratitude may not only motivate prosocial responses toward the sender of gratitude, but whether it may also induce prosocial motivation and behaviour toward third parties.

In the present research we specifically sought to examine this question; we investigated the effect of perceiving an expression of gratitude (e.g., “Thanks”) on the benefactor’s subsequent willingness to help a third party.

7

Perceptions of Gratitude *

Perceiving gratitude in response to helping behaviour might have an incentive value for the benefactor, and thereby, reinforce prosocial behaviour (Skinner, 1938). However, as will be explained below, we do not assume that a reinforcing effect of perceiving gratitude on prosocial behaviour is solely based on its incentive value. To be able to differentiate the effect of perceiving gratitude on a benefactor’s prosocial behaviour from the effects of perceiving other positive responses to helping behaviour, we included a condition in which participants received a material reward as well as a condition in which participants received positive verbal feedback (control condition) into the experimental design. conceptual overview gratitude as an adaptation for altruism

Gratitude has been defined as a cognitiveaffective response to the recognition of an altruistic act, which is “an intentional gesture that is of value to the recipient and costly to the benefactor” (Algoe, Haidt, & Gable, 2008, p. 425). McCullough, Kimeldorf and Cohen (2008) have recently proposed an evolutionary model of gratitude as an adaptation for altruism. According to this model, gratitude serves three functions.

First, it works as a benefit detector, signalling that one has been the beneficiary of someone else’s generosity.

Second, gratitude is thought to facilitate prosocial behaviour of the beneficiary both toward the benefactor and toward third parties.

Evolutionary theory states that for altruistic behaviour to be performed, the expected benefits have to exceed the expected costs to a certain degree (Nowak & Roch, 2006).

Gratitude might raise the benefit-cost-ratio for prosocial behaviour by increasing the expected benefit (McCullough, Kimeldorf, & Cohen, 2008); when people have just received a favour and feel grateful, they might have more trust in other people’s prosocial motivation in general (Dunn & Schweizer, 2005). In other words, we assume that gratitude activates benign expectations regarding other people’s motivation to act prosocial, which results in a heightened expected likelihood that prosocial behaviour will be reciprocated. This increase of the expected benefit lowers the threshold to perform altruistic behaviour.

Finally, and most relevant to the current research, gratitude is thought to reinforce prosocial behaviour of the benefactor, both toward the beneficiary and possibly toward third parties (McCullough, Kimeldorf, & Cohen, 2008).

The expression “Thank you” communicates the recognition and appreciation of the benefactor’s good intention and effort ( Algoe, Haidt, & Gable, 2008). Perceiving appreciation for one’s altruistic behaviour might promote benign expectations (see above) which, in turn, might motivate prosocial behaviour. The crucial question we examine in this article is whether this effect is limited to interactions between the sender and the target of gratitude, or whether it generalizes to the target’s prosocial behaviour toward third parties.

As mentioned above, a second objective of this study is to differentiate the effect of perceptions of gratitude on a benefactor’s prosocial behaviour from the effect of other forms of positive verbal feedback as well as from the effect of a material reward. These latter reactions to helping behaviour resemble gratitude in that they also represent a positive acknowledgement of the helping behaviour.

However, they might not communicate appreciation of the benefactor’s good intention and effort in the same way gratitude does (Algoe, Haidt, & Gable, 2008), thereby possibly usurping the activation of benign expectations on part of the beneficiary; a material reward might activate an exchange mindset on part of the beneficiary, which undermines prosocial motivation (Lepper, Greene, & Nisbett, 1973; Warnecken & Tomasello, 2008; Zhang & Epley, 2009). This point will be explained in more detail below.

Empirical evidence for the evolutionary model of gratitude Effects of experiencing gratitude. In an experiment by Bartlett and DeSteno (2006), participants who had just received help from a confederate were subsequently more helpful not only toward the confederate but also toward a stranger. This increase in helpfulness was mediated by participants’ feelings of gratitude and could not be ascribed to other positive emotions or feelings of indebtedness.

These results are in line with the assumption that gratitude functions to motivate the beneficiary’s prosocial behaviour (McCullough, Kimeldorf, & Cohen, 2008). The observation that participants were also more helpful toward a third party further illustrates that the effect of gratitude on prosocial behaviour is not solely based on the norm of ‘tit- for-tat’ (direct reciprocity).

Prosocial behaviour toward a third party has also been referred to as upstream reciprocity (Nowak & Roch, 2006).

Using a computer simulation, it was demonstrated that upstream reciprocity is of adaptive advantage for a population that has already adapted to direct reciprocity. Thus, gratitude might be a catalyst for

9

Perceptions of Gratitude *

upstream reciprocity, a cognitive-emotional state that keeps a sequence of reciprocal prosocial behaviour going, comparable to a ‘snowball-effect’ (Nowak & Roch).

As noted above, benign expectations regarding others’ likelihood to act prosocial may be of crucial importance in this process. In accordance with this perspective, it has been shown that participants, who described an event when they felt grateful, subsequently reported higher levels of trust toward a third party than did participants, who were asked to describe an event that made hem feel proud (Dunn & Schweitzer, 2005).

Effects of perceiving gratitude. Not only the feeling of gratitude but also the perception of gratitude in the beneficiary seems to facilitate prosocial behaviour (McCullough, Kimeldorf, & Cohen, 2008). A field study demonstrated that restaurant customers who had received their bill with a “Thank you” -note gave higher tips than customers who had received a regular bill (Rind & Bordia, 2006). These results form empirical support for the hypothesis that perceiving gratitude in response to helping behaviour functions to reinforce the benefactor’s prosocial behaviour (McCullough, Kimeldorf, & Cohen).

We argue that perceiving gratitude might promote prosocial behaviour through the same mechanism that experiencing gratitude does, namely by fostering benign expectations regarding other people’s motivation to act prosocial (McCullough, Kimeldorf, & Cohen, 2008).

The expression “Thank you” might signal that upstream reciprocity has been activated on part of the beneficiary. In other words, the benefactor infers that the beneficiary is motivated to act prosocially and that he or she might reciprocate the favour directly or ‘indirectly’ (i.e., via upstream reciprocity). Consequently, the expected benefit for acting prosocial increases; the benefactor is more motivated to act altruistic.

As mentioned above, we assume that receiving a material reward for helping behaviour undermines the activation of benign expectations and upstream reciprocity. Of relevance in this context is research on the overjustification effect shows that a material reward for a favour results in decreased spontaneous helping behaviour as compared to a non-material ‘reward’, such as the expression “Thank you” (Lepper, Greene, & Nisbett, 1973; Warnecken & Tomasello, 2008). A material reward might activate an exchange

mindset, which construes helping behaviour as being based on the norm of tit-for-tat (Zhang & Epley, 2009). Receiving a material reward for helping behaviour might, thus, be perceived as signalling “We’re quit”, meaning that the sequence of reciprocal prosocial behaviour has ended. In contrast to this, the words “Thank you” might be perceived as signalling the activation of upstream reciprocity, meaning that the sequence of reciprocal prosocial behaviour has not come to an end (Nowak & Roch, 2006).

11

Perceptions of Gratitude *

The current research

To summarize, there is some previous evidence for the hypothesis that perceiving gratitude reinforces prosocial behaviour of the target of gratitude toward the beneficiary (Rind & Bordia, 2006; Warnecken & Tomasello, 2008). However, no study has yet investigated the effect of perceiving gratitude on the target’s prosocial behaviour toward a third party. Do the words “Thank you” indeed activate upstream reciprocity? Does a material reward for helping behaviour undermine upstream reciprocity?

We conducted two studies to address these questions. In both studies, we evoked helping behaviour of our participants upon which the beneficiary either expressed gratitude, or handed a material reward to the participant, or expressed acknowledgement of having received help (control condition).

We predicted that perceiving gratitude in reaction to helping behaviour promotes a benefactor’s subsequent prosocial behaviour toward a third party as compared to perceiving mere acknowledgement or receiving a material reward. As noted above, a material reward might activate an exchange mindset (‘tit-for-tat’) which is assumed to undermine prosocial behaviour.

With our second study we aimed to shed more light on the underlying process of a possible reinforcing effect of perceiving gratitude on helping behaviour.

To this end, we modified the control condition by including a positive acknowledgement of the participant’s helping behaviour.

We assumed that positive verbal feedback would not reinforce participants’ prosocial behaviour to the same extent as an explicit expression of gratitude. Furthermore, we assessed participants’ perceived gratitude of the beneficiary (i.e., the confederate) to able to examine whether the intensity of perceived gratitude mediates the effect of the gratitude versus the reward condition on participants’ subsequent prosocial behaviour.

study 1 method

Overview

We evoked helping behaviour of our participants by asking them to fill in some extra questionnaires prior to the ‘actual’ experiment. After having completed these questionnaires, participants received feedback by the beneficiary (“the researchers of the BSI-lab”), which was written on the computer screen; they were either thanked for their help (gratitude condition), or they received a material reward of one Euro (reward condition), or their helping behaviour was merely acknowledged (control condition). Prosocial behaviour was assessed by asking participants to indicate their willingness to volunteer for a charity organization.

Participants

94 participants (29 men, 65 women) took part in this experiment. Ages ranged from 17 to 29 years, with an average of 21.3 years (SD = 2.4). Participants could choose to receive partial course credit or monetary compensation (5 €) for their participation.

Procedure

The experimenter welcomed the participant, brought him or her to the cubicle, started the experiment and left the cubicle. Participants were then asked on the computer screen if they were willing to fill in some ‘extra questionnaires’ prior to the ‘actual’ experiment. Specifically, participants were told that the BSI-lab (Behavioural Science Institute laboratory) had developed some new questionnaires that needed to be validated, and that participants would help the BSI-lab by filling in these questionnaires, which would take five minutes. Through this script, we aimed to evoke helping behaviour in our participants. If the participant agreed to fill in the questionnaire, he or she was presented with several filler tasks, such as rating the emotional valence of Chinese characters.

After having completed these tasks, the experimental manipulation followed. Participants were randomly presented with one of three different screens, representing the three experimental conditions.

In all conditions, the sentence “This was the last part of the questionnaire validation study.” appeared on the screen.

13

Perceptions of Gratitude *

In the control condition (i.e., mere acknowledgement), nothing else was written on the screen and participants proceeded with the ‘actual’ experiment. In the gratitude condition, the sentence “The researchers and employees of the BSI-lab of the Radboud University would like to express their sincere thanks for your help!” also appeared on the screen. In the reward condition, the screen read, “After having completed the experiment, you will receive one Euro extra from the experimenter for your participation.”

Participants then proceeded with the alleged ‘actual’ study, which started with the measurement of the dependent variable, prosocial behaviour. If a participant had chosen not to fill in the ‘extra questionnaire’, the filler tasks were skipped and the participant immediately started with the ‘actual’ experiment.

Eight participants decided not to fill in the ‘extra questionnaire’.

These participants’ data were excluded from the analyses.

Prosocial behaviour was operationalized as participants’ willingness to volunteer for a charity organization of their choice. Afterwards, several demogaphic measures (age, sex, first language, field of study) were assessed and participants completed an instructional manipulation check, which helps to identify participants who do not read the instructions thoroughly (Oppenheimer, Meyvis, & Davidenko, 2009). Eleven participants failed on the instructional manipulation check, their data were removed from the final data sample.

Finally, a funel debriefing was administered, participants were thanked for their participation and received their compensation¹.Three participants indicated suspicion of the experimental hypothesis; their data were excluded from the analyses.

15

Measures

Prosocial Behaviour. Prosocial behaviour was operationalized as participants’ willingness to volunteer for a charity organization. Participants were told that they were going to be presented with a list of various charity organizations they could chose from and that they also had the option to name an organization that was not mentioned in the list. Then, participants were asked to indicate whether they would be willing to do volunteer work for the charity organization of their choice (assessed on a seven-point scale ranging from 1 = “definitely not” to 7 = “definitely yes”) and to specify the amount of time (hours per month) they would be willing to do so. Afterwards, they had the opportunity to choose a charity organization from a list with ten organizations or to name an organization that was not on the list. Responses to the two questions assessing participants’ willingness to volunteer were moderately correlated² , r(69) = .42, p < .001.

Therefore, we decided to combine these items into a new variable by averaging the standardized scores. This composite measure (willingness to volunteer) served as our main dependent variable. ¹

Based on ethical considerations,

not only participants in the reward

Results

The data of two participants were excluded from further analyses as these participants scored extremely high on willingness to volunteer. The final sample consisted of 71 participants (21 men, 50 women)³.

condition, but all participants received one Euro in addition to the regular compensation.

² There were two bivariate outliers, these data were excluded from the correlational analysis.

Prosocial Behaviour

We predicted that perceiving gratitude would reinforce prosocial behaviour while receiving a material reward would undermine prosocial behaviour as compared to perceiving mere acknowledgement for having helped. That is, scores on willingness to volunteer should be highest in the gratitude condition and lowest in the reward condition.

A one-way ANOVA supported this hypothesis, F(2, 68) = 3.54, p < .05. As can be seen in Figure 1, participants in the gratitude condition (M = .39, SD = .20) scored higher on willingness to volunteer than participants in the control condition (M = .05, SD = 20), who scored higher than participants in the reward condition (M = - .41, SD = .20).

³

A one-way ANOVA with

participant gender and condition as fixed factors revealed a main effect of gender on willingness to volunteer, F(1, 35) = 5.45, p < .05. Women (M = .15, SD = .13) reported a higher willingness to volunteer than men (M = - .43, SD = .21).

However, the interaction term was not-significant, F(2, 65) = .20, n.s.

Therefore, gender was not included as a factor in the remaining analyses.

Perceptions of Gratitude *

However, simple contrast tests revealed that only the gratitude and reward conditions differed significantly from each other, t(2, 68) = 2.64, p < .05. The difference between the reward and the control condition, t(2, 68) = 1.62, n.s., as well as the difference between the gratitude and the control condition were not significant, t(2, 68) = 1.03, n.s.

Willingness to Volunteer 0.5

0.39

Willingness to Volunteer (standardized scores)

0.4 0.3 0.2

0.05

0.1 0 -0.1

Reward

Control

Gratitude

-0.2 -0.3 -0.4 -0.5

-0.41 Condition

Figure 1. Willingness to volunteer for a charity organization (standardized scores) by condition

Summary and Conclusions

As hypothesized, participants who had been thanked for their help were subsequently more willing to volunteer for a charity organization than participants who had received a reward of one Euro. Thus, Study 1 provides initial support for the hypothesis that perceiving gratitude reinforces prosocial behaviour.

The control condition did not differ from the other conditions on participants’ willingness to volunteer.

The feedback by the beneficiary provided in the control condition might be ambiguous in the sense that it contains no positive acknowledgement of the helping behaviour. Some participants might have perceived this mere acknowledgement as a lack of gratitude while others might have perceived it as a form of expressing gratitude.

study 2 method

Overview

Study 2 had four objectives. First, we aimed to replicate the findings from Study 1. Second, we enhanced the ecological validity of the experimental design by involving a face-to-face interaction between participant and beneficiary (i.e., confederate). Third, measurement of participants’ perceived gratitude of the beneficiary enabled us to test whether perceived gratitude mediates the difference between the reward and the gratitude condition in participants’ willingness to volunteer. Finally, both the control and the reward condition entailed a positive verbal acknowledgement of the participant’s helping behaviour.

This enabled us to differentiate the effect of positive acknowledgement on a benefactor’s prosocial behaviour from the effects of positive acknowledgement in combination with a reward or an expression of gratitude. Since participants in Study 1 only perceived positive acknowledgement in the gratitude condition, one might argue that the results are not due to a reinforcing effect of perceptions of gratitude but solely to the incentive value of positive (written) feedback. In addition, we enhanced the ecological validity of the experimental design by combining the material reward with positive verbal feedback; rewards are usually accompanied by some sort of positive verbal feedback.

We assumed that positive verbal feedback would rather be perceived as an expression of gratitude when it is not accompanied by a reward than when it is accompanied by a reward. The reward may activate an exchange mindset (see above), resulting in a corresponding perception of the verbal feedback (i.e., “We’re quit.”).

Thus, we predicted that scores on willingness to volunteer should be higher in the control condition than in the reward condition.

Given that an expression of gratitude not only reflects positive acknowledgement but also communicates appreciation of the benefactor’s good intention and effort (Algoe, Haidt, & Gable, 2008), we assumed that participants’ ratings of the experimenter’s gratitude should be highest in the gratitude condition and should be positively correlated with their subsequent willingness to volunteer.

17

Perceptions of Gratitude *

46 participants (20 men, 26 women), most of which were students of the Radboud University Nijmegen, took part in this experiment. Ages ranged from 19 to 50 years, with an average of 22.5 years (SD = 4.7). One additional participant could not take part in the experimental procedure due to a physical handicap.

This participant’s data were excluded from the analyses. Participants could choose to receive partial course credit or monetary compensation (5 €) for their participation.

Prosocial behaviour was then assessed by asking participants to indicate their willingness to volunteer for a charity organization. Afterwards, we assessed several demographic measures (age, sex, first language, field of study) and administered a funel debriefing. Finally, participants were thanked for their participation and received their compensation. Two participants indicated suspicion of the experimental hypothesis and one participant knew the ‘experimenter’ personally. These participants’ data were excluded from the analyses.

Procedure

Measures

Participants

⁴ In order to make sure that any given effects could not be ascribed to specific features of

The alleged ‘experimenter’⁴ welcomed the participant and brought him or her to the cubicle. Just before entering the cubicle, the experimenter pretended to notice a table which was standing in the hallway. He said that he had forgotten to carry this table to another room as part of the preparation for another experiment. He then asked the participant if he or she would be willing to help him carry the table. Through this script,we aimed to evoke the same kind of helping behaviour in all participants.

All participants agreed to help, and together they carried the table to the other room.

the experimenter, we used two confederates who acted as experimenters. Given that we did not hypothesize a three-way interaction between participant gender, experimenter gender and perceived gratitude, we choose to keep the gender of the experimenter constant; both confederates were male. The confederates

Participants were then randomly assigned to one of the following conditions. The experimenter either 1) expressed gratitude by saying “Thank you for helping me out! Now you can begin with your experiment.” or 2) positively acknowledged the participant’s helping behaviour by saying “Okay. Fine. Now you can begin with your experiment.” (control condition) or 3) handed a small material reward in the form of a pen to the participant while saying “Okay. Fine. I have a university pen left. You may have it.

Now you can begin with your experiment.”

received detailed instructions on their role as experimenter.

The participant was brought back to the cubicle, where he or she completed a “computer experiment to investigate the relationship between personality and concentration skills.” After having completed several measures, among which a mood measure and a filler task (an alleged ‘concentration task’), participants completed measures relating to their impression of the experimenter.

Perceived gratitude. To be able to test whether our experimental manipulation was effective, that is, whether participants in the gratitude condition indeed perceived the experimenter as more grateful than participants in the reward condition, we assessed participants’ perceptions of the experimenter.

This was done by presenting participants with a ‘survey’ which allegedly served to “assess the working and quality of the psychological laboratory”. One of the items on this ‘survey’ was, “The experimenter was grateful.” Responses to this item (given on a seven-point scale ranging from 1 = complete disagreement to 7 = complete agreement) served as a measure of perceived gratitude.

Mood. In order to be able to differentiate effects of mood on helping behaviour from those of perceived gratitude arising from the experimental manipulation, mood was assessed directly after the experimental manipulation. This was done by asking participants to indicate their mood by choosing one out of five “smileys” (from smiling to frowning, reverse coded).

Impression of the experimenter Since we sought to manipulate participants’

perception of the experimenter’s gratitude while not affecting their overall impression of the experimenter, we asked participants, “What is your general impression of the experimenter?”. This item was part of the ‘survey’ mentioned above. Responses were given on a sevenpoint scale ranging from 1 = very negative to 7 = very positive.

19

Perceptions of Gratitude *

Prosocial Behaviour.

Prosocial behaviour was operationalized as participants’ willingness to volunteer for a Dutch humanitarian charity organization (Humanitas). We assessed this measure as seemingly unrelated to the rest of the experiment in order to minimize the chances that participants would become aware of the experimental hypothesis. Ostensibly at the end of the experiment, participants were presented with a screen which contained information regarding the objectives and projects of Humanitas.

Next, participants were asked to indicate whether they would be willing to do volunteer work for Humanitas (assessed on a sevenpoint scale ranging from 1 = definitely not to 7 = definitely yes) and to specify the amount of time (hours per month) they would be willing to volunteer. Responses to these questions were highly correlated, r(43) = .62, p <.001. As in Study 1, we combined these items into a new variable (willingness to volunteer) by averaging the standardized scores.

⁵ A one-way ANOVA with participant gender and condition as fixed factors showed no effects of gender on willingness to volunteer, F(1, 35) = .19, n.s. The interaction term was also non-significant, F(3, 25) = .20, n.s.

Thus, gender was not included as a factor in the remaining analyses. ⁶ There were no interactions between condition

manipulation checks

Perceived gratitude

To test whether the experimental manipulation was successful and participants perceived the experimenter as more grateful in the gratitude condition than in the reward condition, a one-way ANOVA with perceived gratitude as dependent variable was performed. The omnibus test was not significant, F(2, 38) = 2.18, p = .13.

However, a simple contrast test revealed that, as predicted, scores on perceived gratitude were (marginally) higher in the gratitude (M = 5.93, SD = .92) than in the reward condition (M = 5.08, SD = .31), t(2, 38) = 2.00, p = .05.

Scores in the control condition (M = 5.31, SD = .31) did not differ from scores in the reward (t(2, 38) = .52, n.s.) or the gratitude conditon, t(2, 38) = 1.46, n.s.

General impression

Results

Two participants scored extremely high (> 2 standard deviations from the mean) on Willingness to volunteer.

The data of these participants were excluded from further analyses.

The final sample consisted of 41 participants (18 men, 23 women)⁵.

The data from the two experimenters were collapsed as no interaction between condition and experimenter was found⁶.

To test whether the manipulation had a unique effect on perceived gratitude in the sense that it did not affect participants’ general impression of the experimenter, a one-way ANOVA with general impression as dependent variable was performed. There was no overall difference between the conditions, F(2, 38) = 1.36, p = .27.

All simple contrast tests were non-significant; participants in the gratitude condition (M = 5.87, SD = .17) did not report a more favourable impression of the experimenter than participants in the control (M = 5.54, SD = .18) or the reward condition (M = 5.92, SD = .18).

and experimenter on perceived gratitude, F(2, 35) = .38, n.s or on willingness to volunteer, F(2, 35) = 1.13, n.s.

Mood

We conducted a one-way ANOVA with mood as dependent variable to check whether the effect of the manipulation on perceived gratitude was not confounded by mood effects.

The omnibus test did not reach significance, F(2, 38) = .47, n.s.

Participants in the gratitude condition (M = 4.00, SD = .17) did not report a more positive mood than participants in the reward (M = 4.23, SD = .18) or the control (M = 4.08, SD = .18) condition.

21

Perceptions of Gratitude *

main hypotheses

Prosocial Behaviour

As in Study 1, we predicted that participants would be most willing to volunteer for a charity organization in the gratitude condition and least willing in the reward condition.

A one-way ANOVA supported this hypothesis, F(2, 38) = 3.51, p< .05.

As can be seen in Figure 2, participants in the gratitude condition (M = .35, SD = .24) scored higher than participants in the control condition (M= .16, SD = .26), who scored higher than participants in the reward condition (M = -.56, SD = .26).

However, simple contrast tests revealed that only the difference between the gratitude and the reward condition was significant, t(2, 38) = 2.55, p < .05. The difference between the reward and control condition was marginally significant, t(2, 38) = 1.94, p = .06.

The gratitude condition did not differ from the control condition, t(2, 38) = .54, n.s.

Willingness to Volunteer 0.35

Willingness to Volunteer (standardized scores)

0.4 0.16

0.2 0 -0.2

Reward

Control

Gratitude

-0.4 -0.6

-0.56

-0.8 Condition

Figure 2. Willingness to volunteer for

Humanitas (standardized scores) by condition.

Additional Analyses

Correlational analysis. To provide further support for the main hypothesis, we conducted a correlationtal analysis. Given that participants rated the experimenter as more grateful in the gratitude than in the reward and control conditions and having shown that participants were more willing to volunteer in the gratitude than in the

reward condition, we hypothesized a positive correlation between perceived gratitude and willingness to volunteer.

This analysis revealed a moderately strong positive correlation between perceived gratitude and willingness to volunteer, r(41) = .31, p < .05. Thus, across conditions, the more participants perceived the experimenter as being grateful, the more willing they were to volunteer.

Mediation by perceived gratitude

To summarize the most important results so far, participants were more willing to volunteer in the gratitude than in the reward condition, there was a positive correlation between perceived gratitude and willingness to volunteer, and participants perceived the experimenter as more grateful in the gratitude than in reward condition. Given these findings, the conditions for a mediation by perceived gratitude are met for the difference between the gratitude and the reward condition.

As Figure 3 illustrates, the zero-order correlations were significant. However, when willingness to volunteer was regressed onto perceived gratitude and condition simultaneously, the effect of condition reduced significantly, Sobel t(28) = 1.60, p = .05.

23

Perceptions of Gratitude *

Perceived Gratitude

general discussion

Figure 3. Perceived gratitude as a mediator of willingness to volunteer. Numbers in parentheses are zero-order correlations. The other numbers are coefficients for a model regressing willingness to volunteer on perceived gratitude and condition simultaneously. Condition was dummy-coded (0 = reward, 1 = gratitude). *p < .05. **p < .01

Summary and Conclusions

Study 2 provides further evidence for the hypothesis that being the target of gratitude reinforces prosocial behaviour; participants who had been thanked for their help were subsequently more willing to volunteer for a charity organization than participants who had received a small material reward.

This effect was mediated by the intensity of perceived gratitude and could not be ascribed to mood effects or differences in participants’ general impression of the experimenter.

Furthermore, participants who had received positive acknowledgement for their help (control condition) were more willing to volunteer than participants in the reward condition, suggesting that positive acknowledgement might either be sufficient to activate upstream reciprocity or might be interpreted as gratitude.

It is important to notice that the mean ratings of perceived gratitude were relatively high (> 5, assessed on a sevenpoint scale) and had a small variance (< .32) in all conditions.

Thus, small variations in perceived gratitude predicted participants’ willingness to help a third party. This provides further support for the notion of gratitude as an adaptation for altruism.

Across two studies, we predicted and found that participants, who had been thanked for their help, were subsequently more willing to volunteer for a charity organization than participants, who had received a material reward.

The present research is the first to provide empirical evidence for a reinforcing effect of perceptions of gratitude on a benefactor’s prosocial behaviour toward third parties.

Study 1 participants reported a higher willingness to volunteer after having read an expression of gratitude than after having read that they were going to receive one Euro.

Thus, Study 1 provided initial support for the hypothesis that perceiving gratitude facilitates prosocial behaviour toward third parties.

Study 2 was designed to shed more light on the underlying process as well as to enhance the ecological validity of the experimental design. By involving a face-to-face interaction between participant and beneficiary, we were able to assess participants’ perceptions of the beneficiary’s gratitude. The main result of Study 1 was replicated; participants in the gratitude condition reported a higher willingness to volunteer for a charity organization than participants who had received a material reward. As predicted, this difference was mediated by participants’ perceptions of the beneficiary’s gratitude and could not be ascribed to mood effects or differences in participants’ general impression of the experimenter.

This finding in particular provides support for the notion of gratitude as an adaptation for upstream reciprocity; the perceived intensity of a benficiary’s gratitude can predict a benefactor’s prosocial behaviour toward a third party.

Participants who had received a material reward in response to their helping behaviour were less willing to volunteer than participants who had perceived positive acknowledgement. This result corroborates with findings of earlier studies demonstrating an undermining effect of material rewards on prosocial behaviour (Lepper & Greene, 1973; Warnecken & Tomasello, 2006).

As outlined above, we assume that receiving a material reward for spontaneous helping behaviour undermines prosocial motivation by

25

Perceptions of Gratitude *

activating an exchange mindset. In order to test this hypothesis, future researchers may consider measuring the degree to which participants think in terms of tit-for-tat (i.e., exchange mindset).

Interestingly, we found an undermining effect of an unexpected material reward; this result seems to be in conflict with the assumption that only expected material rewards have an undermining effect on people’s intrinsic motivation (Lepper & Greene, 1973). The fact that we observed this undermining effect after a singular ‘exposure’ also seems to contradict earlier studies on the overjustification effect, in which several exposures to the material reward were necessary for the effect to occur. It is possible that the kind of helping behaviour we evoked in our participants was strongly intrinsically motivated, so that the reward induced cognitive dissonance, which might have resulted in increased avoidance motivation. Future researchers could investigate this process by measuring participants’ approach-avoidance motivation as well as their perceptions of the material reward.

Another challenge for future researchers in this area is to further differentiate the effect of perceptions of gratitude on a benefactor’s prosocial behaviour from the effect of other forms of positive verbal feedback. The present research suggests that positive acknowledgement might be sufficient to activate upstream reciprocity; there was no difference in the prosocial behaviour of participants who had perceived positive acknowledgement and those who had perceived gratitude. Possibly, people expect an expression of gratitude for a favour ‘by default’ so that they tend to perceive positive acknowledgment as an expression of gratitude.

The expression “Thank you” communicates both appreciation for the benefactor’s good intention and effort and a feeling of satisfaction or happiness on part of the beneficiary (McCullough et al., 2008). Which of these aspects is (more) central to the reinforcing effect of perceptions of gratitude on prosocial behaviour? In Study 2, participants who had received a mildly positive acknowledgement for their help (“Fine.”) showed an increase in their subsequent prosocial behaviour as compared to participants who had received a material reward.

This implies that positive acknowledgement is necessary to activate upstream reciprocity. Perceived happiness might, then, moderate the intensity of the benefactor’s subsequent prosocial

motivation and behaviour toward third parties. Further research is needed to differentiate perceptions of appreciation for one’s helping behaviour from perceptions of the extent to which one has benefitted the other person.

A limitation of the present research is that it does not include a measurement of participants’ cognitions regarding other people’s motivation to act prosocial even though these cognitions were assumed to facilitate upstream reciprocity.

Future researchers may consider assessing participants’ trust in other people as well as more general cognitions pertaining expectations around other people’s prosocial motivation.

Additional mechanisms

So far, we have discussed the present results mainly in light of the evolutionary model of gratitude as an adaptation for altruism. I would now like to address two additional mechanisms that may be relevant with regard to the current findings.

First, participants’ increased willingness to volunteer for a charity organization might be a self-enhancement strategy. Being the target of gratitude, that is, perceiving appreciation for one’s altruistic behaviour might promote people’s self-esteem and motivate a striving for more positive affirmation (Crocker & Park, 2004).

If this is indeed the case, perceptions of gratitude should predict increased levels of self-esteem.

A third possible mechanism might be self-perception. Participants who received a material reward, signalling an exchange mindset on part of the beneficiary, might have attributed an exchange mindset to themselves, that is, they might have inferred having acted out of a sense of obligation (Zhang & Epley, 2009). By the same token, participants who perceived gratitude in response to their automatic helping behaviour might have self-attributed an intrinsic prosocial motivation.

One way of determining whether attributions based of self-perception can explain the observed effects, would be not to measure participants’ perceptions of the beneficiary’s gratitude until after measurement of the dependent variable since the measurement itself stimulates participants to think about the interaction.

Practical Implications. The practical implications of the current findings are profound. Exponents of charity organizations, who aim to raise funds for their cause or search for

27

Perceptions of Gratitude *

volunteers, could apply the main finding of this research through not giving any material rewards to potential supporters who show spontaneous interest in their cause, but instead through expressing their gratitude.

This strategy could also be applied to the design of websites, where sentences such as â&#x20AC;&#x153;Thank you for your attention.â&#x20AC;? should be incorporated more frequently and distinctively visible. Open internet platforms such as YouTube(c) are a vivid demonstration of the function gratitude as a facilitator of prosocial behaviour. Charity organizations may consider stimulating interactions (face-to-face as well as virtual) between their clients and volunteers so as to create more opportunities for clients to express their gratitude, and, thereby, for gratitude to unfold its snowball-like working as a catalyst for prosocial behaviour.

To conclude, the present research is the first to demonstrate that perceiving gratitude may not only affect interactions between benefactor and beneficiary, but that its reinforcing effect may generalize to interactions with third parties.

29

Perceptions of Gratitude *

references

Algoe, S.B., Haidt, J., & Gable, S.L. (2008). Beyond reciprocity: Gratitude and relationships in everyday life. Emotion, 8, 425-429.

Bartlett, M.Y., & DeSteno, D. (2006).

Gratitude and prosocial behavior: Helping when it costs you.

Psychological Science, 17, 319-325.

Cicero, M.T. (1851). The orations of Marcus Tullius Cicero, Vol. III (C.D. Younge, Trans.). London: George Bell & Sons.

Crocker, J., & Park, L. E. (2004). The costly pursuit of self-esteem.

Psychological Bulletin, 130, 392 - 414.

Dunn, J., & Schweitzer, M.E. (2005). Feeling and believing: The influence of emotion on trust.

Journal of Personality and Social Psychology, 88, 736-748.

Hume, David (1739). A treatise of human nature: being an attempt to introduce the experimental method of reasoning into moral subjects.

Vol. 1. London: Printed for John Noon.

Emmons, R.A., & McCullough, M.E. (2003).

Counting blessings versus burdens: An experimental investigation of gratitude and subjective well-being in daily life.

Journal of Personality and Social Psychology, 84, 377-389.

Lepper, M. R., Greene, D., & Nisbett, R. E. (1973).

Undermining children’s intrinsic interest with extrinsic reward: A test of the “overjustification” hypothesis.

Journal of Personality and Social Psychology, 28, 129-137.

McCullough, M.E., Kimeldorf, M.B., & Cohen, A.D. (2008).

An Adaptation for Altruism? On the social causes, social effects, and social evolution of gratitude.

Current Directions in Psychologicial Science, 17, 281-285.

Nowak, M., & Roch, S. (2006). Upstream reciprocity and the evolution of gratitude. Proceedings of the Royal Society of London, Series B: Biological Sciences, 274, 605-609.

Oppenheimer, D.M., Meyvis, T., & Davidenko, N. (2009). Instructional manipulation checks: Detecting satisficing to increase statistical power. Journal of Experimental Social Psychology, 45, 867-872.

Skinner, B. F. (1938). The behavior of organisms. New York: Appleton-Century-Crofts. Warnecken, F., Tomasello, M. (2008).

Extrinsic rewards undermine altruistic tendencies in 20-month-olds.

Developmental Psychopathology, 44, 1785-1788.

Wood, A.M., Maltby, J., Gillett, R., Linley, P.A., Joseph, S. (2008).

The role of gratitude in the development of social support, stress, and depression: Two longitudinal studies.

Journal of Research in Personality, 42, 854-871.

Zhang, J., & Epley, N. (2009). Self-centered social exchange: Differential use of costs versus benefits in prosocial reciprocity.

Journal of Personality and Social Psychology, 97, 796-810.

31

Perceptions of Gratitude *

33