I don't think it's necessarily the "lack of aggression", because I've seen my wife drive! I think it may be more of intimidation with regard to the (seemingly) numerous rules of racing.

Of the female crews I've seen, most are more than aggresive enough to handle a boat in tight quarters, but perhaps lack the assertiveness to ask to skipper. Either that, or our fragile male egos won't give up the stick...

There have been times when I feel I would be better crewing to get the boat speed where I need it, but then think I should be on the helm because I think (tactically) we should be doing something different (like banging the corner or closing the door on some people creeping up the middle). Until my communication skills improve, I think I will continue to frustrate myself...

But I see the advantage to the big person being crew:
- better leverage and the ability to use two hands to pull strings (mainsheet, downhaul or spin sheet)
- mobile weight to keep boat trim optimal
- Ability to board competitors boats and slaughter crew if they get to close at a rounding (Abast ye, matie.. ARRRR!)