Just like penguins and other primates, people trade sex for resources

[Mr. McD]

New research shows that even affluent college students who don't need resources will still attempt to trade sexual currency for provisions, said Daniel Kruger, research scientist at the University of Michigan School of Public Health.

The exchange of resources for sex---referred to by scientists as nuptial gifts---has occurred throughout history in many species, including humans, Kruger said. The male of the species offers protection and resources to the female and offspring in exchange for reproductive rights. For example, an arranged marriage can be considered a contract to trade resources.

However, the recent findings suggest that such behaviors are hard wired, and persist no matter how much wealth, resources or security that people obtain.

http://www.ns.umich.edu/htdocs/releases/story.php?id=6472