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.