I can’t remember where I read it but a psychologist said males and females descended in part from ancestors who spent a lot of time in trees.
A vestige of those days is shown in a theater audience. In a sudden shocking scene in a horror or suspense movie, men put up their hands , sometimes starting to make fists, to begin a reflex to fight.
Women pull up their legs under them toward the seat. This was because dangling feet in the trees could be grabbed by predators and rival tribe members to pull the females down.
The old reflex survives.
Instincts. Like dogs walking in circles before laying down. Way back before being domesticated they’d do that to beat down the grass/weeds to make a nice bed. It’s not to make sure they didn’t lay on a snakes like some think. Snort!