I took part yesterday in a good event organised jointly by the Chartered Management Institute and Women in Management, under the joint leadership of Ann Francke and Sandra Pollock.   Ann interviewed Cherie Blair.  Cherie referred to studies which show that if a woman thinks she can do only 90% of a job she tends not to go for it, whereas a man who thinks he can do 60% will not hesitate.  I don't know of any research on this, but  from anecdotal conversations (for instance with recruitment agencies) had formulated something very similar, as part of the third PP factor: psychology/self-confidence.  My rule-of-thumb is that if men think they can do 70% of…