I think there is something to be said for your analysis.
However, I have definitely slept with women who are the opposite. One woman I dated had low self-esteem about her looks and was shy, and it showed in her dress and body language. But when we were alone in the bedroom she was sexy, free-spirited, loud, and hip to pretty much anything. As my sweet old grandma always used to say - strangely - "it's the shy ones you have to watch out for."
one tip I'll give is that if you see a woman that you think will be boring in bed, and you see her loosen up a lot when she starts having a drink or two, or when she's with her friends, then you know she has that wild side to her but it only comes out when she's really comfortable or her shield is down. She might be worth the risk
