Chimpanzees Imitate Social Behaviors to Strengthen Bonds

**Chimpanzees are influenced by observing social behaviors like grooming and play in others, a concept known as 'behavioral contagion,' according to a study by Georgia Sandars and colleagues at Durham University, published in PLOS ONE.** This behavior has been previously noted in various animals for activities such as yawning and vigilance against predators, but its presence in friendly activities like grooming and play in chimpanzees had not been explored until this study. Researchers observed 41 chimpanzees in a Zambian sanctuary and found that grooming and play are contagious across different ages, ranks, and sexes. **Importantly, the contagion of grooming was stronger when observed in individuals with close social bonds, whereas play behavior was most contagious among younger chimpanzees, regardless of their social ties.** This suggests that while play is crucial for the social and behavioral development of the younger chimps, grooming serves to build and repair relationships among adults. The study highlights that close social ties may enhance attention and influence, possibly due to attachment or even jealousy, which in turn strengthens group cohesion through shared behaviors.