Social interaction, a basic survival strategy for many animal species, helps maintain a social environment that has limited conflict. Social dominance has a dramatic effect on motivation. Recent evidence suggests that some primate and nonprimate species display aversive behavior toward food allocation regimens that differ from their peers. Thus, we examined the behaviors displayed by mice under different food allocation regimens. We analyzed changes in food intake using several parameters. In the same food condition, the mice received the same food; in the quality different condition, the mice received different foods; in the quantity different condition, one mouse did not receive food; and in the no food condition, none of the mice received food. To test differences based on food quality, one mouse received normal solid food as a less preferred reward, and the other received chocolate chips as a high-level reward. No behavioral change was observed in comparison to the same food condition. To test differences based on food quantity, one mouse received chocolate chips while the other received nothing. Mice who received nothing spent more time on the other side of the reward throughout the experiment. Interestingly, highly rewarded mice required more time to consume the chocolate chips. Thus, under different food allocation regimens, mice changed their behavior by being more hesitant. Moreover, mice alter food intake behavior according to the social environment. The findings help elucidate potential evolutionary aspects that help maintain social cohesion while providing insights into potential mechanisms underlying socially anxious behavior.
Social Anxiety and Social Behavior: A Test of Predictions From an Evolutionary Model
