'The subject’s wrist position allows the partner to support the weight of the subject’s clasping arm, which can be viewed as a prosocial act by the partner. They found females engaged in palm clasping, whereas males engaged in wrist clasping, which they say could be the males trying to assert dominance. That is the process of two chimps holding and shaking hands at the end of, or during a grooming sessions, with distinct variations in how they are carried out per group.Īs well as differences between groups, the team also found differences between male and female chimpanzees clasping hands. They found one sustaining social activity that changed depending on the group, but remained the same among members of the same group - grooming handclasps.

The new study looked at a range of material and social cultural activities in two groups of chimps over 12 years, excluding any activities linked to adaptive value - social foraging and personal interactions. That study was a focus on material culture, but the authors of this new study said few have explored long-term social culture. 'These findings indicate that human culture, including its arbitrary social conventions and long-term stability, is rooted in our evolutionary history.' This discovery was the case 'despite substantial changes in group compositions across the study period,' according to the authors of the study.Īll of the chimps also had several behavioural variants within their repertoire unique themselves and independent of the handshaking process.ĭespite all of this the chimps still maintained within the group and between the group consistencies of behaviour similar to the 'cultural phenomenon in humans'. They found that the chimps 'adhere to arbitrary group-specific handclasp preferences' that can't be explained by genetics or the environment they are in. The team behind this study used a large dataset spanning 12 years to explore chimpanzee social interactions and behaviour within two distinct groups. Moreover, there is a lack of evidence proving cultural stability in animals spreading across generations and persisting within specific groups. While material culture, such as teaching tool use, has been reported across the animal kingdom, indications of social culture in animals are limited. Culture is a hallmark of the human species, both in terms of sharing information about new inventions, such as tools, and adhering to social conventions.

Chimpanzee hand grips