Does hunger make you more egoistic?

Being hungry is not pleasant. Many of us become bad-tampered, irritated or even nasty when hungry. But does hunger also makes you more egoistic? Are people more likely to act in their self-interest and share less, when hungry? There are several psychological theories and empirical findings that would suggest that.

In a series of psychological studies, an international team of psychologists from Germany (Universities of Giessen, Hildesheim, and Bamberg), the Netherlands (VU Amsterdam), and the UK (University of Oxford) tried to answer this question. In two experimental studies, participants were asked not to eat anything for at least 12 hours prior to the experiment. Thus, all participants arrived at the laboratory very hungry and with a low blood glucose level. Before the start of the experiment, half of the participants – the control condition – received food like chocolate pudding to relief their hunger and to increase the blood glucose level. The other half of the participants – the experimental condition – did not receive any food and proceeded with the experiment while they were still hungry.

In the experiments the participants then worked on a series of tasks designed to test egoistic behavior. For example, in some of these tasks participants were given an amount of money (e.g., €10) and were asked to share it with other participants. In other tasks, participants had to cooperate with others to increase the amount of money they were receiving. Moreover, in some of the tasks, participants had the opportunity to punish egoistic behavior of others. The researchers expected that hunger should promote egoistic behavior. However, there was no support that hunger promoted egoistic behavior, as hungry and non-hungry participants did not differ in their willingness to share and to cooperate.   

In a further study, the researchers examined if egoistic behavior in hungry people is more likely to show when food had to be shared instead of money. To this end, the researchers set up a booth in front of the canteen of the University of Giessen. They asked students entering the canteen (i.e., hungry participants) and students leaving the canteen (i.e., not hungry  participants) to play the Dictator Game. But this time only half of the participants were asked to share money, whereas the other half shared food (small packages of trail mix). In line with the other studies, there was no evidence that hunger makes more egoistic, independently if participants shared money or food.   

“Our results reveal that, although acute hunger might increase egoistic impulses, this does not necessarily result in more egoistic behavior. We speculate that some other social needs may take primacy in affecting egoistic behavior. One strong candidate is the concern with reputation as a cooperative person, as shown in many previous studies on human cooperation.” summarizes Jan Häusser, Professor of Social Psychology at the Justus-Liebig-University Giessen.

Interestingly, the article also includes a study examining people’s general beliefs, showing that people generally believe that hunger does make people more egoistic. So, people’s beliefs do not seem accurate. Why then do people have these beliefs? One of the authors, Paul van Lange, Professor of Psychology at VU Amsterdam, “We have seen in prior research that people tend to overestimate egoistic behavior and motives in other people. The myth of self-interest seems quite multifaceted, and seems to include the firm belief that under needy circumstances people show their true self, which they believe is largely egoistic. We know now that at least for acute hunger this is likely to be an overstatement.”

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University of Bamberg
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