Primate Behavior: Chimps Select Smart Tools, Monkeys Intentionally Beg

ScienceDaily (July 18, 2012) — Chimpanzees use weight to pick the best tool, and monkeys beg more when they're paid attention to, as reported in two independent research reports published July 18 in the open access journal PLoS ONE.

In the chimp study, researchers found that the chimpanzees used weight to choose the best hammer to crack open nuts. Nut cracking is one of the most sophisticated instances of tool use in chimpanzees, and learning how to do it has been shown to be very difficult for some chimps. In work led by Cornelia Schrauf of the University of Vienna, the researchers showed that the chimps were able to choose the best tool to crack nuts based solely on the weight of the tool. Schrauf notes, "Experience clearly affected the subjects´ attentiveness to the relevant tool properties. Whereas the most skilled chimpanzee showed a preference for the most efficient hammers from the early beginning of the experiment, the unskilled individuals became selective over time."

Continued:  http://www.sciencedaily.com/releases/2012/07/120718192005.htm