Chimp tricks.

LiveScience sullies our image of chimpanzees as noble, natural creatures with evidence that these apes practice prostitution:

The primates’ food-for-sex barter occurs indirectly, over the course of weeks or months, with males seeming to accrue credit with the ladies by plying them with meat killed on a hunt.

“What people have been looking for before is an immediate exchange,” [Cristina] Gomes [of the Max Planck Institute for Evolutionary Anthropology] told LiveScience. “I included all interactions between a pair that occurred over several months to see if there was more of a long-term relationship. I suspect this is why I found a correlation that nobody else had found before.”

To establish that tit-for-tat was going on, rather than just friendship (which could also explain why one chimp would give another food), the researchers tried to control for other factors. By tracking association patterns between pairs, the scientists found that males didn’t just give meat to females they hung around with often. They specifically gifted food to those that they ended up copulating with. Additionally, factors such as rank and age also did not explain the connection between giving away meat and mating success.

Dinner and a show?