From Emotional Contagion to Prosocial Behavior: A comparative review of endothermic Amniotes

Questions regarding whether and how non-human animals experience emotions have become an increasingly important topic in behavioral and cognitive research across species. Capacities that were once thought to be reserved solely to humans, such as empathizing and targeted helping, have by now been identified in a range of mammals and birds despite marked differences in cognitive complexity. This thesis reviews existing literature on the related but distinct phenomena of emotional contagion, empathy and prosocial behavior and compares findings across mammals and birds. It aims to provide an overview of contemporary definitions, theoretical frameworks, experimental paradigms and behavioral evidence applied and investigated over recent years. Simultaneously, this review addresses common obstacles in this field such as inconsistent terminology and difficulties in interpreting animal emotions and motivations across taxa, thereby identifying targets of future research. Emotional contagion describes a widespread and evolutionarily conserved mechanism, which although cognitively simple serves important functions in parental care and social bonding. Empathy research distinguishes between affective and cognitive components and has been organized using models such as the Russian Doll and Combination model, with current findings suggesting that affective empathy is widespread across species, whereas evidence for cognitive empathy remains inconclusive. Prosocial behavior encompasses all observable acts that result in a benefit for the recipient, possibly yielding immediate or delayed costs or benefits for the donor. The interplay of these related phenomena indicates that socio-emotional behaviors are more common and diverse among non-human animals than previously anticipated, as they rely on evolutionarily conserved mechanisms and serve analogous functions.