Men are the competitive gender. In past, only 40% of men survived to reproduce whereas 80% of women did.

Not in absolute terms, but imagine if more competitive men survive with higher probability in each generation, there's a good chance males will be more competitive and females will be more cooperative in next generations.

Now this theory is fringe. But not as nonsense as "Both genders are same, everything is social conditioning" bullshit we hear every day.

So given that gender specifically is a social concept, there is historical but not necessarily biological causation at play.