*eyebrow raised* Ok I'll bite...
Some Basics:
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Biology: Pain is the body's way of telling the brain something is hurting and you should stop doing it because you risk permanent damage and loss of functionality. The body also has means of supressing the sensation of pain fue to chemical responses which vary differently in men and women.
Sociology: Pain is also expressed differently due to traditional gender roles. Men are taught from an early age to not cry and to just carry on even if it hurts.
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Men are capable of shruging off fights better but this might also be in part to the testosterone/adrenaline rush that got the fight started in the first place. Men also tend to have larger muscle masses so being punched would also hurt less initially as opposed to women who typically have no muscle mass or desire to obtain said muscle mass as men do. This is why a kick in the groin is typically tauted as being so incredibly painful, you cannot develop muscle on your nutsack.
Thanks to the above scenario, we can see that on average men are subjected to medium-to-high pain levels a lot less frequently that women are if taken in an identical instance-driven situation. (not practical for real world applications though, like adolescent boys get beaten up a lot more frequently than adolescent girls do)
The situations where the level of pain is virtually equal such as with the flu (because muscle mass is doing jack shit for you right now) means that men are being subjected to pain levels they're not traditionally accustomed to. However, when looking at this objectively, it would be said that most men exadgerate the pain claims in order to get out of work or responsibilities.
However then there are examples of males who are used to the pain of colds/flus and build a natural tolerance to them. From personal experience I can say my father, who gets sick maybe twice a decade, acts as if he's on his deathbed whereas I, who get sick roughly 6 times a year, act as if everything's the norm but usually exadgerate the claims so get out of uni/work a lot easier.
Subjecting both genders to high-to-extreme levels of pain (torture) results in man's natural tendencies, both chemical and sociological, to withstand the pain a lot better. Of course seeing as no case study in the world would get away with extreme torture (I don't mean water boarding, I mean sticking red-hot iron in your eye balls) on its test subjects it becomes a hard claim to verify.
Final verdict: The biggest contributing factor is experience and repeated exposure to the sensation; or in simple English, getting used to it. But we can see in extreme cases of pain such as mortal injury or prolonged torture than men win through sheer biological advantage over women. This of course has little to no importance in a standard lifestyle so it becomes a moot point.
