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If you've ever been around animals, you know they can have different personalities. Some dogs love meeting new people and making dog friends; some would rather just watch the world go by.

Some cats love cuddling; others don't want anything to do with you. And research has backed up the idea that other species have different personality traits, just like us. But even though these personalities can be as diverse as the ones in your friend group or office, there was one personality trait scientists used to believe was uniquely human: conscientiousness.

It's that trait that makes you work hard and make responsible decisions, and scientists didn't traditionally see it in most non-human animals. Recently, though, researchers have started to see that many other species do demonstrate conscientiousness—actually, a lot like us. And that goes to show that this trait we thought differentiated us from other animals might actually make us more similar to them than we thought.

Personality is a tricky thing to describe, but in humans, psychologists often describe it using the Big Five. You might have heard of the Big Five if you've ever taken a personality test it includes five key traits that try to quantify aspects of someone's personality: extraversion, agreeableness, neuroticism, openness to experience, and conscientiousness. And you can describe someone by ranking how much they demonstrate each trait.

The traits themselves seem to be pretty universal. You can see them in different people from all different times and places. And you can use a person's specific traits to predict how they might act in certain situations.

For example, someone who ranks low for extraversion, in other words, an introvert, is more likely to skip out on a party than someone who's more extraverted. The thing is, though, a person can pretty easily take a survey and tell you what personality type they are. But you can't exactly ask a dog or bird to do that.

The one thing you can do is watch these animals and keep track of how they behave. Since personality is a good predictor of behavior, you can also work backwards:. By seeing how an animal behaves, you can piece together its personality.

That's how researchers figured out that other animals have personalities that look a lot like ours. Like, a dog that's always jumping up on visitors and making friends with the neighborhood pups is likely more extraverted than a dog that keeps to itself. And it's not just domestic species, even octopuses seem to have different personalities, based on how sociable they act or how easily they let people approach them.

But for a long time, researchers only saw four of the Big Five in non-human animals, conscientiousness was mostly missing. And they could sort of understand why that might be the case. Conscientiousness involves being diligent, orderly, and focused on achieving goals.

So psychologists had originally imagined that to be conscientious, you had to be thinking about the future. Like, you might study for a test so you can do well in school and get a good job later. But for the most part, animals aren't known for planning ahead.

Except, recent studies have suggested that an animal doesn't need to be thinking about the future to be conscientious, and that many species have been demonstrating this trait all along, we've just been looking at them the wrong way. In a review from 2017, a group of researchers came up with a creative way to study conscientiousness in animals, by reviewing hundreds of studies that had already been done. Essentially, they looked for studies that showed the animals behaving in ways we'd describe as conscientious if they were human.

That way, they'd avoid having to guess what was in the animals' minds they'd look directly at how they acted and use that to infer their personalities. And they found hundreds of examples of these animals acting in ways that we'd generally consider conscientious. Like, within one species of writing spiders, individuals showed a different amount of dedication to their webs.

Some were sloppier, while others wove consistent, orderly patterns. In another case, some blackbirds and song thrushes kept their eggs neatly arranged in the nest, while others were less finicky. And a study of bee colonies found that not just individual bees but the colony as a whole can have a personality.

For instance, some colonies were super diligent about making repairs to the hive and cleaning out dead bodies, and others, not so much. This type of conscientiousness, which the researchers described as orderly, mostly showed up in insects and birds. But in mammals, the researchers often found a different aspect of conscientiousness: one that had more to do with competence and achieving goals.

Like, research has shown that cows get excited when they learn something new, and their heart rates go up a little, just like humans. And dogs vary in how good their posture is, the ones that sit with better posture seem to be better learners. These behaviors might not represent actual planning; they might just be instinct.

But what's interesting is that the individuals or colonies that were more conscientious did end up being more successful. Tidier webs caught more prey, neatly arranged nests were less prone to brood parasites, and well-kept hives had lower risk of disease. Dogs with good posture were even better at picking up new tricks!

So, even though it wasn't a result of planning, in a way, it was related to some beneficial future outcome, a lot like human conscientiousness is. This research strongly suggests that the Big Five applies to other species just as it does to us. In fact, that could even tell us something about where this trait in humans comes from.

Conscientiousness may have evolved in different animals for different purposes, but species closely related to us seem to benefit from this trait for a few reasons. For one, we all tend to have complex social structures that depend on us being able to share and cooperate, so being orderly and following rules can be an advantage. Researchers have also proposed that conscientiousness is helpful for choosing good long-term mates, which species like ours tend to do.

This suggests that conscientiousness, like other personality traits, is rooted in our evolution. In humans, researchers have even found some brain regions involved in conscientiousness. For instance, the prefrontal cortex often becomes active when we exercise impulse control, or plan for the future.

There's evidence of similar activity in dogs' brains when they inhibit impulses, too. Overall, research seems to point to the fact that the personalities of non-human animals are complex, a lot like ours. And the trait we sort of thought made us human likely makes us even more like other animals than we knew.

Thanks for watching this episode of SciShow Psych! And a special thanks to our patrons on Patreon, who keep SciShow going. If you're interested in joining the amazing community of supporters who make videos like this possible, you can find out more at patreon.com/SciShow. [♩OUTRO].