It's a classic action movie trope, the tough guy or gal walking away from an explosion as cool as you please. There are some people who pretty much walk through their lives that way, and science has proven the badass—or depending on your perspective, jackass—walk is real.
Psychology researchers at the University of Portsmouth in the U.K. did personality assessments on some 29 people then did motion capture studies of the same subjects as they walked at a normal pace on a treadmill.
The findings were pretty interesting: any of the study participants who walked with "exaggerated movement of both the upper and lower body" were displaying aggression. In the Science Daily account of the study, researcher Liam Satchell explained the differences between the average laid-back person's friendly amble and forceful march of the angry:
"When walking, the body naturally rotates a little; as an individual steps forward with their left foot, the left side of the pelvis will move forward with the leg, the left shoulder will move back and the right shoulder forward to maintain balance. An aggressive walk is one where this rotation is exaggerated."
To reinforce conclusions from the motion capture, psychologists followed up with a series of questions as well as a personality test that determined five main traits: "openness, conscientiousness, extraversion, agreeableness and neuroticism."
There's a bit of a dark side to studies like this. As one researcher indicated, the ability to map bodily motions to an individual's potential for aggression could theoretically be used to stop crime before it happens. Security cameras linked to smart computer programs geared toward spotting criminals might flag someone before they ever pulled a gun or flashed a knife.
Anyone who just knows the value of putting out a certain vibe to make sure no one messes with you might find that prospect a little too spooky and big brother-like to handle.