I can't help but roll my eyes at this one a bit. I'm assuming you're referring to Hurd & Bailey's studies in intrauterine testosterone exposure vs finger length in adulthood. Although there is some good face validity with this research, their methods and results lead to some big questions.
How much testosterone were the subjects exposed to in utero, and what is the relationship between finger length? Well, we don't know how much they were exposed to, because this was extrapolated, not measured. They also tested a small population of undergraduate students (300, IIRC). There is always the possibility that another factor better accounts for the results - especially in such a cohesive group. A possibility that turns up in most research that is not double blind (not to say that double blind is the only valuable research - but that's neither here nor there in this case).
The specious part however, is the part that asserts "in utero testosterone exposure levels dictate in turn a fair degree of masculinization in an individual". That I flatly don't believe, and there is no way to prove it one way or another. The statement, by its nature, is limited to being intuitive knowledge. "Masculinization" is a social feature. Established, determined and measured in a social context. I don't believe it can be teased out in a nature vs nurture argument, and I'm really starting to believe that the whole nature vs nurture is beside the point anyway, as one can never occur without the other...
On the other hand, in
my case, a large rack greatly affects how I spend my money...