Alloparental infant-carrying behaviour in Common Marmosets (Callithrix jacchus)

In many animals, individuals will often help each other. By benefiting others at their own expense, helping behaviour can affect the survival and reproductive success of helpers and, as a consequence, may appear maladaptive. I investigated helping behaviour in a captive population of a small monkey, the common marmoset, in which elder siblings help their parents to care for their infant siblings. My findings show that this helping behaviour was not influenced by the immediate benefits or costs for the elder siblings. These findings provide insights into the evolution of helping behaviour derived from altruistic motives.