WHEN it comes to grooming, female baboons seem to have a lot in common with
commodity traders.
Most primatologists believe that baboons groom each other to cement long-term
strategic allegiances that will give the animals a competitive edge. But Peter
Henzi of the University of Natal in South Africa, and Louise Barrett of
Liverpool University believe they have a better explanation. They say baboons
exchange grooming for more immediate favours within a “biological market”. Such
commodities are controlled by individual animals, and can usually only be got by
trading.
“People make an awful lot of assumptions about grooming, and now that’s being…



