Who does more of the cleaning: you or your roommate?

It's you, right? Sure, you forgot to take out the trash that one time, but that was the day your alarm didn't go off, so it's pretty understandable.

But she always leaves her dirty dishes around, and she never seems to vacuum. She's a great friend, but let's be honest, kind of a slob. If you've ever felt like you work harder than everyone else around you, you're definitely not the only one.

But you're also probably wrong. See, your view of yourself is skewed by what's known as self-serving bias, where people tend to view themselves in a good light. They'll attribute positive events to themselves, and negative ones to external circumstances.

This happens in sports all the time, when the refs make a controversial call. If your team loses, you're convinced that bad call is why you lost the game. But if the call's against the other team and your team wins … well, it probably didn't make that much of a difference, right?

You guys got to win anyway, obviously. People also tend to think they're better than everyone else. It's called the better-than-average effect: in studies, when people are asked how they compare to others, they rate themselves as above average.

But that's not how averages work. I mean, somebody has to be below average. On top of that, people are convinced that they do more work than everybody else.

A study published in The Journal of Personality and Social Psychology in 1979 found that when 37 married couples were asked who did more of the couple's shared tasks, like cooking, the total was almost always more than 100%. Like, one partner would be sure she cooked 70% of the time, while the other would report that he made 50% of the meals. Which, you know, isn't how percentages work.

That study's has been replicated multiple times, and people consistently think they do more work than their partner does. We're so convinced that we're great, because whether things go right or wrong, this bias saves face. It helps you hang on to your self-esteem.

We all like to think highly of ourselves, and self-serving bias actually feels good. In one experiment, people were asked to think about social situations while they were having their brains scanned in an fMRI machine. Thirty people were presented with 80 statements each — things like, “a friend sent you a postcard,” or, “a friend told you a lie.” They were then supposed to imagine this happening in real life, think about what might have caused it, and press a button blaming the event on the situation, themselves, or someone else.

But the researchers found that people were much more likely to blame something bad -- like, “a friend told you a lie” -- on the situation or on someone else, instead of blaming it on themselves. But they also found that making those self-serving attributions activated a part of the brain called the dorsal striatum. It's associated with selecting actions, like whether to turn left or right in a maze, and determining the probability that those actions will ultimately lead to a reward.

So the fact that the dorsal striatum lit up suggests that self-serving bias is rewarded in the brain. Where the real trouble comes in, though, is that we tend to do the opposite for those around us. With other people, we commit what's called the fundamental attribution error.

We think they act the way they do because of their personalities, rather than because of the circumstances of the situation they're in. In other words, instead of thinking that your roommate is really busy or really distracted by something going on at work, you jump straight to “What a slob!” But why? The first factor is the availability heuristic, which is the tendency to think that an event is more common if you can recall more specific instances of it.

You vividly remember every time you scrubbed the bathroom, but you might not have always been around every time your roommate did. Even if you clean exactly the same amount, your brain does some guessing based on the times you can remember and decides that you're doing much more of the work. Then there's the actor-observer bias, which is all about perspective.

When you're evaluating yourself, what's happening around you is the most prominent thing. You see yourself in multiple situations, so it's pretty obvious that changes in the environment or the circumstances cause changes in how you act. But when you evaluate others, your focus is often on them.

Their behavior is what's most visible to you, and you don't usually see them in all the different environments and circumstances that might affect them. Which means that it's easy to come to the conclusion that your lab partner is lazy or your boss is a jerk. Of course, it's not great to walk around assuming that other people are terrible.

So is there anything you can do to avoid these biases? It's definitely tricky. Studies suggest that you can even be biased about these biases: you tend to think other people are much more likely to commit them than you are.

But just being aware of biases can make you less likely to commit them. At least you'll know that you should think twice before you blame someone for the way they're acting, or assuming that they never take out the trash. Because let's be real: you want to be on good terms with your roommate.

After all, she knows where you live. Thanks for watching this episode of SciShow Psych, brought to you by our patrons on Patreon! If you'd like to support us, you can go to patreon.com/scishow.

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