Extroverted gorillas in captivity outlive their shy brethren, a new study of these great apes in North American zoos and sanctuaries finds.

Using methods adapted from studying human personality, keepers, volunteers, researchers and other caretakers gauged 298 individual gorillas' temperaments. These gorillas were followed over 18 years and their life spans recorded. The results revealed the the more sociable, active, playful and curious the gorilla, the longer it was likely to live.

The results are consistent with studies finding that human extroverts outlive introverts, too, study researcher Alex Weiss of the University of Edinburgh said in a statement.

"These findings highlight how understanding the natural history of personality is vital to ensuring the continued health and well-being of humans, gorillas and other great apes," Weiss said.

Studies of centenarians — people who live to be 100 or more — have found that positive, outgoing people seem more likely to hit the century mark. A study published in May 2012 surveyed 243 centenarians and found most to be outgoing, optimistic and easygoing. These personality traits may arise from underlying genetics, which also influence health, the researchers told LiveScience when the study came out.

The new gorilla study, published today (Dec. 5) in the journal Proceedings of the Royal Society B, asked humans who knew the gorillas well to rate the animals' dominance, extroversion, neuroticism (a measure of anxiety that has been linked to shorter lives in humans) and agreeableness. They found that only extroversion was linked to life span.

This extroversion-longer life link wasn't affected by the gorilla's gender, age at assessment or how many times the gorilla had been moved from facility to facility.

Copyright 2012 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.