Selfish strategies develop in social problem situations in chimpanzee (Pan troglodytes) mother-infant pairs

Shinya Yamamoto, Masayuki Tanaka
DOI: 10.1007/s10071-009-0276-2

Abstract

Humans employ various strategies, including selWsh and altruistic strategies, depending on the situation. In order to examine whether non-human animals show such Xexibility or not, we analyzed chimpanzees’ selWsh and cooperative behavior in two types of social problem situations. In this study, we tested chimpanzee mother–infant pairs in two adjacent booths, each equipped with a vending machine. When a token was inserted into a vending machine, the vending machine delivered food rewards to the adjacent booth. In experiment 1, a partition between the two booths was open. In experiment 2, the partition was closed and a mother and her infant were placed in separate booths, so that reciprocal cooperation was essential for them to receive rewards. The participants did not cooperate reciprocally in either experiment. In experiment 1, the chimpanzees developed selWsh tactics to get rewards and changed their tactics Xexibly according to the partner’s behaviors. In experiment 2, in which they could not receive rewards without cooperation, they stopped altogether inserting tokens. In both cases, the infants stopped cooperating Wrst. These Wndings support the idea that chimpanzees are primarily competitive rather than cooperative. Chimpanzees’ high social intelligence might be demonstrated in the Xexibility of their selWsh tactics, but not in the form of reciprocal cooperation at least when food is involved. We suggest that the failure to establish reciprocal cooperation was due to the social relationship between the mother and her infant, which was characterized by infant’s privilege and mother’s tolerance.
Keywords

Chimpanzee, Mother-infant relationship, Reciprocal cooperation, Self-regard, Social problem situation,

Article Information
Yamamoto S, Tanaka M(2009)Selfish strategies develop in social problem situations in chimpanzee (Pan troglodytes) mother-infant pairs Animal Cognition, 12, S27-S36. https://dx.doi.org/10.1007/s10071-009-0276-2
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