Edit: Also, this book by a threat assessment specialist talks about problems faced by women in particular who have the fear response in mild form, but suppress it. His conclusion is that the emotional response can actually be a lot clearer and more accurate than the intellectual one in a dangerous situation and it is wise to listen to it. If that man chatting you up is making you nervous, it's a sign you ought to be careful.
The lesson from the book is that fear is a second signal (in addition to reasoning) that may heighten perception of a dangerous situation and should not be ignored.
Get dozens of book recommendations delivered straight to your inbox every Thursday.