are women over-critiquing themselves?

A question I’ve always had is if women don’t present themselves as vigorously as men because they are too critical of themselves.

Do we somehow assume we know less than the guys we work with? Do we hold ourselves back because of a lack of self-confidence? A self-gender-judgement?

And if so… how do we get ourselves to step beyond that, to grow a thicker skin against our own self-prejudice?