On: I regularly hire women for 65% to 75% of what male...

[highfreq]

Another factor could be that earlier interviews weed out the forceful negotiators among the women, because that personality trait makes women less likable. On the other hand, a lack of aggressiveness makes men appear weak.

[marquis → highfreq]

There are many ways to negotiate without appearing aggressive. I'm sure 50% of the population can alert you to some of these methods.