It is fairly common that biological causation is suggested or suspected when dealing with a difference in outcomes along gender lines. Sex hormones as an factor for behavior is usual one of the first suspect, especially if the difference is found around or after puberty. There are historically a huge number of studies done on testosterone to demonstrate this leap done by both researcher and public opinion.

That said, much of those studies where later found to be mostly wrong, and testosterone tend to be a bad predictor and a very weak influence on behavior. It seems more that hormones have a stronger influence on shaping culture than it has on shaping behavior.