I would guess that most people will have maybe a dozen or so direct supervisors during their working lives - maybe more if you changed jobs a lot; maybe less. Chances are that if you are old like me, more of them will have been men - just because until relatively recently it was more difficult for women to get to be bosses. Most of my bosses were men, not only because I'm old but also because most of my jobs were in male-dominated industries. A few of those men were terrible bosses, a few were great, and most were so-so. I also had a few female bosses. None were as spectacularly awful as the worst male boss, one was excellent, and the other two were neither good nor bad. On the basis of my personal experiences I can't offer a conclusion about the relative awfulness of male vs. female bosses. I do know that humans of both genders are capable of treating others very badly.