Altruism Studies Flashcards
What did Bshary (2002) find?
Studies cleaner-client reef fish interactions. They found that clients approach cleaners that they observe cooperating with their client and avoid cleaners that they observe cheating. Cleaners that cheat frequently are avoided more frequently than cooperative cleaners.
What did Clutton-Brock (2002) find?
In cooperatively breeding invertebrates, nonbreeding helpers raise young produced by dominant breeders. There is evidence that helpers can be unrelated to the young, suggesting that cooperative breeding has no evolved due to kin selection.
Heinsohn and Packer (1995)
Lions will hunt cooperatively when prey is difficult to catch but cooperation often breaks down when the prey is relatively easy to catch. Experimental studies have shown that when the pride attack a stranger, certain individuals will consistently lag behind their companions during the groups response. It was found that some females cooperate unconditionally and others only cooperated when most needed. Although leaders recognise laggers, they continue to lead the response.
Stevens and Hauser (2004)
Animals often aid others without gaining any immediate benefits. Donors typically help because they or their kin receive future benefits or avoid costly punishment. This suggests that reciprocal altruism in non-human animals is constrained by psychological mechanisms.
Holmes and Sherman (1982)
Showed that sibling recognition in squirrels is in part based on association in the nest. Some sibling pups were reared by one mother (their own or foster), some were reared aoart by different mothers, non-siblings were reared as a single litter and non-siblings were also reared apart. When older it was found that regardless of genetic relatedness pups reared together rarely fought. Unrelated individuals reared together were no more aggressive towards each other than true siblings reared together. This suggests that individual learn who their kin are from association in early life.
