It's a common stereotype that short people (and shorter men especially) tend to be a lot angrier and more confrontational than their taller counterparts. Indeed, I've often heard that shorter guys are more dangerous in a fight because they feel like they have more to prove. For many years, this neurosis has been called a "Napoleon Complex."

The Napoleon Complex postulates that shorter people have an inherent sense of inferiority as a result of their height, and this means they're more likely to pick fights and challenge others in order to display their own dominance. The name of this neurosis comes from the French dictator Napoleon, who in real life was actually of average height for someone of his nationality and time period. However, he was often portrayed as being dwarf-sized in British propaganda, and because he was always surrounded by far taller bodyguards.

However, the Napoleon complex has never been scientifically verified as a real-life psychological phenomenon... until now. A recent study published in the Association for Psychological Science has found that small men are more likely to be indirectly aggressive when competing for resources with tall people.

The researchers first conducted a pilot study using male and female participants; asking them to fill in a short questionnaire about their personal feelings about their own height. The participants then met with each other another in a relaxed social setting, before sitting down to play the Dictator Game. In this exercise, the participants sat in isolated cubicles and were given eight €1 coins. They could take as many coins as they liked, but the ones they left would be given to the others.

The men who claimed that they often felt small took more coins for themselves, while taller people took less and shared more. However, shorter women took no more coins than their average-sized counterparts, which suggests that the Napoleon complex is a strictly male issue. This seems to suggest that, while short men might not be aggressive to your face, they might be sneakier when you back is turned and will take more than their fair share. The study suggests a compelling link between male insecurity and height/physicality.

The study ultimately concluded:

"Across three studies, we found preliminary support for the Napoleon complex—the idea that short men compensate behaviorally in dyadic intrasexual competitions with taller rivals, by behaving more indirectly aggressively in resource contests ... Consistent with predictions from sexual selection theory, and in line with the Napoleon complex, short men kept more resources in competitive interactions, using height cues to assess the appropriateness of different behavioural tactics to take these resources from their male rivals."

So there you have it: if you know any short dudes out there with a chip on their shoulder; you now have scientific proof that they're grumpy because of their own short stature. Just don't mention it to their face: you might live to regret it.