In the battle over which sex is stupider, a group of male researchers may have proven that men win hands down.
That males are more likely to engage in risk-seeking behavior and face emergency hospital admissions as a result has already been well-documented, but a new study published in British medical journal BMJ also noted that men excel at a special class of truly "idiotic" risk.
"Idiotic risks are defined as senseless risks, where the apparent payoff is negligible or non-existent, and the outcome is often extremely negative and often final," the study said, setting out a so-called male idiot theory. In its annual end-year issue, the BMJ often publishes "lighter hearted" research, although it must still meet the journal's standard requirements, including peer review.
"According to 'male idiot theory' (MIT) many of the differences in risk seeking behavior, emergency department admissions, and mortality may be explained by the observation that men are idiots and idiots do stupid things," it said.
The study examined 20 years of winners of the Darwin Award, which is given out to people who remove themselves from the gene pool in ways that make a clear distinction between accidental and idiotic deaths.
"For instance, Darwin Awards are unlikely to be awarded to individuals who shoot themselves in the head while demonstrating that a gun is unloaded. This occurs too often and is classed as an accident," the study noted. "In contrast, candidates shooting themselves in the head to demonstrate that a gun is loaded may be eligible for a Darwin Award—such as the man who shot himself in the head with a 'spy pen' weapon to show his friend that it was real."
Using only incidents confirmed by the Darwin Awards Committee and excluding urban legends, unverified accounts, honorable mentions and couples, the study found a marked difference in the sex of award winners, with men taking home the gold nearly 89 percent of the time.
"This finding is entirely consistent with male idiot theory (MIT), and supports the hypothesis that men are idiots and idiots do stupid things," the study said.
Indeed, the study cited multiple examples of winners who appear to have lacked the ability to attempt risk management.
In one example, office workers watched a construction worker demolish a car park in an adjacent lot for two days, speculating on how he would remove a final support to crash it down safely.
"They discovered, on the third day, that he didn't have a plan. The concrete platform collapsed, crushing him to death and flattening his mini-excavator," the study noted.
Differences in how socially acceptable excessive alcohol consumption can be also appears to play an important role, the study noted.
"Anecdotal data support the hypothesis that alcohol makes men feel 'bulletproof' after a few drinks, and it would be naïve to rule this out," it said. "For example, the three men who played a variation on Russian roulette alternately taking shots of alcohol and then stamping on an unexploded Cambodian land mine. (Spoiler alert: the mine eventually exploded, demolishing the bar and killing all three men.)"
To be sure, the study noted some potential weaknesses with the data collection, such as the possibility that women might be more likely to nominate men for Darwin Awards or that the award committee might have a selection bias.
In addition, "Idiotic male candidates may be more newsworthy than idiotic female Darwin Award candidates," the study noted.
While citing a possible evolutionary advantage to idiotic behavior, with "individuals selflessly removing themselves from the gene pool," the study's authors said they believed the theory is likely flawed.
"Presumably, idiotic behavior confers some, as yet unidentified, selective advantage on those who do not become its casualties," it said. "Until MIT gives us a full and satisfactory explanation of idiotic male behavior, hospital emergency departments will continue to pick up the pieces, often literally."
—By CNBC.Com's Leslie Shaffer; Follow her on Twitter @LeslieShaffer1