Do women blink half as often?

No, this is not supported as a general rule. Studies of spontaneous blinking have reported different results: one sample blinked more often among women (19 versus 11 times per minute), while another study of young adults found no significant sex difference. Blinking also varies with age, attention, and task. The claim that women blink “twice less often” cannot be generalized; in the cited study, the direction was actually the opposite.