chimp
© Robert WeinkoveChimpanzee eating figs in Kibale National Park
Richard Wrangham of Harvard University and Sonya Kahlenberg of Bates College in Maine published research in the December 21, 2010, issue of Current Biology, a Cell Press publication that demonstrates the first evidence that chimpanzee youngsters in the wild may tend to play differently depending on their sex.

The research was reviewed at EurekaAlert and a draft of the research paper can be downloaded from this site.

The basic findings are:
  • Female chimpanzees play with sticks in a manner resembling a mother chimpanzee caring for an infant.
  • A biological (evolutionary) predisposition to play with dolls in a manner imitating mothers caring for infants is proposed as superlative to sex-stereotyped socialization roles in female humans.
  • The same type of behavior has been observed in the captivity in the wild with chimps but this is the first observation of this type of behavior involving "toys" created by the chimpanzees themselves.
  • Young female chimpanzees were observed playing with and carrying sticks more often. This play included taking the sticks into their day nests and demonstrated behavior similar to mothers caring for young chimps.
The researchers argue that this may be a single chimpanzee group learned behavior because this is the first known observation of that behavior but argue that it may be indicative of an evolutionary trait and a behavior that has been carried over from apes to humans.

Further research of other groups of chimps could verify the concepts.

The research is based on fourteen years of observation of the Kanyawara chimpanzee community in Kibale National Park, Uganda.

Dr. Wrangham's "Chimp Blog" (with lots of chimp photos) can be read here.