most well known for his proposal that men
like the appearance of breasts
because of their ressemblance to genital flares
indicating periods of fecundity
Why I call him a pseudo-scientist? It's encapsulated in the above, but I will decrypt my thought compression: in my (admittedly brief) anthropological career, I was taught that Mr. Morris was good at getting lots of press for hypotheses not because they were likely or proveable but because they dealt with topics interesting to the general public such as evolutionary gender roles and, well, sexy stuffs. From what I know of him (having only read the book which is your namesake) he's definitely a good speculator, responsible for increasing the profile of the field of anthropology in the public eye and perhaps ultimately benefiting the field through the increased interest, but contributing little fact to its body of knowledge himself.
Were it not for persons such as himself paleoanthropology and primatology would be virtually unknown fields; hard scientists view paragons of the fields such as Jane Goodall and Dian Fossey as well-intentioned mascots but also not particularly scientific. It is also true that without the benefit of a time machine much of paleoanthropology, the study of extinct possible-human-ancestors, will forever be mere speculation; this is not a reason not to study it, but it is a reason to view its results as less scientific than, say, non-quantum physics.
I believe the correct thing for you to do, apey, is to refute me and convince us that he -is- a scientist and therefore deserving of our belief.