Scientists have identified a mental mechanism that people use to subconsciously gauge threats posed by others.
The mechanism translates the magnitude of the threat into the same dimensions used by animals to size up their adversaries - size and strength - even when these dimensions have no actual connection to the threat, researchers said.
"In choosing between fight and flight, we rely on a little picture in our heads that adjusts the size of every potential foe we encounter according to how formidable he seems to us to be. The more likely we believe the individual is to win a fight, the bigger and stronger he seems to us," said University of California, Los Angeles anthropologist Daniel Fessler.
The research illuminates how people make decisions in situations where violent conflict is a possibility, which could have ramifications for law enforcement, the prison system and the military.
"There's an old system in our brains that's used when we decide whether to be physically aggressive and it's a very efficient shortcut to gauge danger, but it can mislead us," said Colin Holbrook.
In the study's first phase, Fessler and Holbrook presented Americans with descriptions of two men - one who participates in several dangerous sports including freestyle motorcycling and big-wave surfing, and another who is so risk-averse that he can't bear to even watch big-wave surfing.
The respondents consistently perceived the daredevil to be taller and stronger than the man who avoided the extreme sports.
To ensure that the effect wasn't unique to American culture, the team also assessed perceptions of risk-seeking behaviour among men on the Fijian island, where one of students happened to be conducting research at the time.
The team even tested whether there was an actual correlation between height, muscularity and risk-seeking behaviour in the US, but found none.
"Risk-prone behaviour doesn't have a literal connection to size and strength, yet is conceptualised in those terms," Fessler said.
"Risk-prone individuals make for dangerous enemies - if someone isn't worried about getting hurt or dying, he's someone you don't want to mess with," said Fessler.
Fessler and Holbrook also have shown that perceptions can run in the other direction, making a potential foe seem smaller and weaker.
