Humans are snap judgment machines. With only the flimsiest-seeming evidence, we form firm and far-reaching opinions of others (that's why first impressions are so important and lasting). And while those judgments can sometimes be biased, science is showing they're also often correct.

We're not crazy, it turns out, to read a lot into someone's posture, face, or even smell. When scientists look closely they find these subtle clues really can accurately predict our personalities. Take a new study on walking and personality from an international team of scientists as one example. 

Fast walker? You're either a New Yorker... or an extrovert.

Folk wisdom has long associated fast walking with certain urban environments (hello, New Yorkers!) and a go-getter attitude. Meanderers are thought to be lost in their own thoughts, while many would guess uptight walkers are uptight people. Is there any truth to these intuitions? This new study suggests yes.

When the scientists examined data on both the walking styles and personalities of more than 15,000 adults of all ages, strong patterns emerged. "Fast walkers are more likely to be extroverted, conscientious and open to new experiences," reports PsyBlog. "Neurotic people, though, tended to walk more slowly."

Extroverts stay speedy.

But what about age, you might ask? We all, of course, tend to naturally slow down as we get older, but according to this study not everyone slows down at the same pace.

"Personality not only influenced walking speed, it also affected how gait changed over time. Those who scored lower on neuroticism and higher on extraversion, conscientiousness, and openness had a slower decline in walking speed compared to their counterparts," reports Medical Daily. Their report also notes that these findings coincide with older research that suggests those with "higher neuroticism and lower conscientiousness have less physical activity and more sedentary behavior."

What's the takeaway here? You can't, obviously, change your personality by speeding up or slowing down, but this research suggests you can probably change how you are perceived. Want to come off as bold and fearless? Charge in. Want to seem thoughtful? Take your time.

These insights may be even more useful though as another addition to the toolbox of tricks that can help you assess a person's character on the fly so that you can suss out instantly who you are dealing with in a meeting, on a date, or just crossing the street.