To whom are these women reporting said pain tolerance, and how would they know? Are they into the wierd stuff? How come I wasn't invited to at least be the cameraman? These are burning question that demand answers.

I wonder if it is related to this strange phenomenon

"Of those who report their rapes, around 4–5% also describe experiencing orgasm. But the true numbers are likely much higher. In a 2004 review paper, a clinician reports, "I (have) met... several female victims of incest and rape who had lubrication and orgasm.""

-Tribal encounters often result in the victor slaughtering all the males and incorporating the females. This process is described in of all places, the bible.

And the females who could survive this brutality may have developed defenses against physical and mental trauma, which could include reduced pain and even orgasm.

And from a genetic perspective warfare is the ultimate male/male competition, and women prefer to judge relative quality in potential donors by causing them to compete.

So the victors would have proven themselves as more worthy of repro rights since the now defunct tribesmen were unable to defend theirs.

'Alls fair in love and war.'

Both males and females want to determine who they are going to mate with. This desire obviously manifests in different behaviors.

Some even believe that rape was prevalent during the Pleistocene

"It is possible that sexual coercion may actually enhance female fitness by providing a behavioral filter for higher quality males as mates or guaranteeing that females' sons will carry sexually antagonistic traits that enable them to achieve higher reproductive success (Eberhard 1996; Cordero and Eberhard 2003). If the net effect on female fitness is therefore positive, then sexual conflict becomes a mechanism of female choice, which Eberhard (2005) contends explains most male mating aggression to resistant females. " - Conflict and Bonding Between the Sexes
Ryne A. Palombit

-and if so, a womans survival strategy may have been to try to convince her attacker to spare her life during the attack itself. Hence

"the group also showed that the female brain does not shut down..."