Bonobo power

It is geenrally believed, at least by the broader public, that chimpanzees are competitive and aggressive, whereas bonobos are cooperative and peaceful. There is certainly some truth in this, but I think that it is suspect, since the tw species where studied by researchers from different nationalities: chimapnzees by English, and bonobos by Japanese (mainly). Is it not possible that the researchers projects the dominant values of their society on the apes? This is an easy mistake, in particualr if you are not aware of which are the dominant values of your society with respect to the others.