Speaker
Description
Prosocial behavior is defined as any behavior that is intended to benefit another individual. This behavior does not need to be costly. Results of individual studies are heterogenous, obscuring major effects. We conducted a phylogenetically controlled meta-analysis in order to investigate how much variation in non-human mammalian and avian prosocial behavior can be explained by the cooperative breeding hypothesis and by different experimental approaches. We examined if variation in prosocial behavior in the prosocial choice task can be predicted by the extent of allomaternal care and techniques. We calculated Hedge’s g as the effect size to compare the outcome of conditions for the actor and the recipient for the comparison of mutualistic (1/1) vs selfish (1/0). We compared the test condition, i.e. partner present, to different controls conditions, i.e. partner absent or random chance. We classified the experimental design according to the techniques used in the experiment (prosocial choice task: pulling, touch, token). We conducted meta-regressions to assess the influence of the test conditions, allomaternal care and techniques on the 136 test and 49 control effect sizes from 45 studies. Actors chose the 1/1 option more than the 1/0 option in the test than in the control and more than by random chance, and these results support that non-human mammals and avian actors behaved prosocially. The extent of allomaternal care and techniques did not significantly affect the effect sizes, which did not support the cooperative breeding hypothesis nor differences in outcomes based on experimental techniques.
