The dawn of social bonds: what is the role of shared experiences in non-human animals?

Abstract

Group-living animals can develop social bonds. Social bonds can be considered a type of social relationship characterized by frequent and consistent affiliative (non-reproductive) interactions. Social bonds with conspecifics bring many advantages, also in terms of direct fitness. A characteristic of social bonds is that they need time to develop. Several studies on humans have emphasized the fact that sharing experiences can affect the strength of social bonds. A similar trend can be spotted in non-human species. For example, a recent experiment showed that if chimpanzees watched a video together with a conspecific, they spent more time in proximity compared to conspecifics with whom they did not actively watch a video. Another experiment on fish showed that individuals who experienced a situation of high predation risk together, showed preference for each other compared to those who did not. As the link between shared experiences and social bonds is not explicitly recognized in non-human animals, the main goal of this work is to propose the exploration of this novel research path. This exploration would contribute to shed light on the evolutionary mechanisms of social bond (or friendship) development and maintenance between individuals in different vertebrate species, from fish to non-human primates.

Social ageing: exploring the drivers of late-life changes in social behaviour in mammals

“…in birth rates, death rates, and dispersal rates) and developmental traits cause the force of natural selection to change with age [34], which should influence age-based changes in social behaviour by altering who is available for interaction, including similarity to others in traits or states (their level of homophily), as well as familiarity and relatedness of group members. It has been shown, for instance, that similarity in age [13,151,153] and shared experience [154] [156], which, in some specific contexts, is suggested to play an important role in selecting for late-life helping behaviour, such as the cessation of females' reproduction in favour of promoting their offspring's reproductive success [42,157]. However, in addition to affecting decisions 'to breed' or 'not to breed' [156], changes in local relatedness might also affect the rates and distribution of affiliative or agonistic interactions.…”

“…in birth rates, death rates, and dispersal rates) and developmental traits cause the force of natural selection to change with age [ 34 ], which should influence age-based changes in social behaviour by altering who is available for interaction, including similarity to others in traits or states (their level of homophily), as well as familiarity and relatedness of group members. It has been shown, for instance, that similarity in age [ 13 , 151 , 153 ] and shared experience [ 154 ] are important drivers of the strength of social relationships. As an individual ages, they are likely to lose individuals with whom it has grown up and shared time, leading to the loss of important social connections.…”

Forced proximity promotes the formation of enduring cooperative relationships in vampire bats

“…If individuals that were forced to associate in the same small cage similarly perceived these shared experiences as negative, would this weaken or strengthen the process of social bonding? Animals might prefer partners with whom they share rewarding experiences because of simple associative learning; alternatively, negative or stressful experiences that are shared might facilitate or reinforce partner choice [ 25 ]. For instance, guppies that were exposed to an environment where they perceived high predation risk were found to exhibit stronger partner preferences for one another than those that were not [ 26 ].…”

Forced proximity promotes the formation of enduring cooperative relationships in vampire bats

“…If bats that were forced to associate in the same small cage similarly perceived these shared experiences as negative, would this weaken or strengthen the process of social bonding? Animals might prefer partners with whom they share rewarding experiences because of simple associative learning; alternatively, negative or stressful experiences that are shared might facilitate or reinforce partner choice [25]. For instance, guppies that were exposed to an environment where they perceived high-predation risk were found to exhibit stronger partner preferences for one another than those that were not [26].…”