www.independent.co.uk/life-style/manspreading-scientific-explanation-revealed-men-behaviour-public-transport-etiquette-a7862771.html
An article from last year. Male scientist mansplains manspreading to the female population and basically "because pelvis" is the answer.
Except, I as a human female find it far more comfortable to manspread too. I don't because it is anti social and because I was taught almost from birth that it wasn't lady like to sit like that and actually inappropriate. Male science man seems unaware totally of the fact that we tell little girls to set with their legs closed.
For me the "lady like" way to cross one's legs is hugely uncomfortable. I didn't do it because my pelvis was arranged that way, I did it because I was told it was the correct way to sit for a girl. Sitting knees together is just as bad.