Pink is not feminine. Blue is not masculine. The moment you are born you are assigned one of these colors based solely on your genitals, which you have no control over. A color will modify your interactions with other humans your entire childhood.
This theory can only be argued and tested within a society which implicitly believes men and women are fundamentally different. Thus, it's unlikely and difficult to create experiments which could truly test this in an unbiased manner.
This could be tested by cloning someone with Klinefelter syndrome (XXY) multiple times, and removing an X chromosome in some in the zygotes of the clones, and a Y chromosome in others. Scientific evidence implies that they will be born with different genitalia, i.e., are fundamentally different.
The archetypes of male and female persons vary significantly between different cultures, subcultures, heterotopiae and times. This suggests that personality traits and behavioral patterns associated with either sex are subject to the environment a person is socialized in.
Almost all civilisations throughout time and places have exhibited roughly the same gender roles: the man provides for the woman and his family. Either this is a natural manifestation of inherent biological differences, or there is a vast patriarchal conspiracy set up to maintain male dominance!
Many gender differences did not appear until later parts of history, meaning the differences did not always exist and were created by society. Young boys were once allowed and encouraged to wear dresses, it was considered gender neutral and was only marked feminine due to new views from society.