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If you haven't gotten to your midlife crisis yet, you're probably not looking forward to it. According to pop culture, people hit their forties and suddenly become miserable— and to deal with it, they quit their jobs, buy sports cars they can't afford, and have affairs with much younger people.

Yikes. Still, if you think about it, it's pretty weird to think that turning a specific age would be enough to make us upend our lives. So is the midlife crisis really a thing?

Well, it's kind of complicated, but there's probably less to worry about than you think. The term midlife crisis was coined by psychoanalyst Elliott Jaques in 1965. He believed that you had your crisis when you realized that you'd already lived more than half your life.

He studied quote-unquote geniuses, like Bach, Shakespeare, and Mozart, most of whom either died tragically or became much more prolific after their late 30s. He thought that the fear of not accomplishing everything they wanted to either killed them or lit a fire under them. Admittedly, he also thought that this didn't really apply to women, because they went through menopause instead.

That's clearly not accurate, but because of it, most midlife crisis stereotypes today are still about men. Of course, other thinkers at that time were also talking about developmental crises. And the one who really popularized the idea of the midlife crisis was researcher Daniel Levinson.

In 1975, he proposed that life was made up of a series of stable periods interspersed with crises known as transitional periods. He based his stages on work from previous psychologists and on his own study of 40 American men aged 35 to 45. Levinson thought that the biggest transition, which happened in middle age, had to do with a sense of not accomplishing enough.

He believed it could be dealt with by learning to set more reasonable goals. Still, tiny sample sizes of one group aren't always reliable, so more recently, researchers have tried looking for the midlife crisis in bigger, more diverse samples—and they seem to have found it. One trend that has emerged is a U-curve in reported happiness levels.

People seem to be happy early in life and at the end of it, but they slump in the middle. This trend has been found in multiple studies, looking at over a million people in more than 50 countries. In 2013, one researcher proposed a possible explanation for the U-curve pattern, after analyzing a 13-year-long German study of 23,000 people.

He said it had to do with expectations. According to his hypothesis, young people expect to beat the average when it comes to careers and happy relationships. And when things don't quite work out that way, they're disappointed.

They do eventually adjust their expectations, but not always fast enough to prevent that disappointment. The result is pessimism and dissatisfaction—a double whammy of misery. But at some point, as they get older, those expectations do align with reality— possibly because, according to some research, the aging brain is less prone to regret.

Life starts getting better… and because expectations are lower, it's a pleasant surprise that brings people back up the curve. Now, if this all sounds pretty depressing, it is worth mentioning that the U-curve isn't set in stone. It's still pretty hotly debated for a number of reasons.

For one, several recent studies have found that well-being simply increases as we age, without the middle-age dip. And there are some issues with the studies that showed the U-curve, too. Many of them are cross-sectional studies, meaning that they look at lots of different-aged people and use them to estimate trends over the lifespan.

This is different from a longitudinal study, which follows the same subjects over a long period of time. Longitudinal studies can be more accurate for long-term research, but not many have been done about midlife crises. Until recently, old age, childhood, and adolescence were studied much more often than middle age.

Still, the longitudinal studies that have been done tend to show that steady increase in well-being. That could mean cross-sectional studies aren't entirely accurate, but we'll need to do more research to know for sure. There's also an issue of definitions.

You might call a midlife crisis a difficult transition that occurs around age 40. But different researchers have different criteria:. Is it stressful?

Is it eventful? Is it internally- or externally-driven? Even when researchers do agree, the public's definition tends to be much broader.

A 1992 study found that just 10% of people had had midlife crises when the researcher determined whether they met the right criteria. But, in a 2000 study, when people were directly asked if they'd had a midlife crisis, 26% of them said yes. The public's definition of this is similar to researchers', but tends to include any stress or turmoil encountered between 30 and 65.

So the idea of the midlife crisis may prevail in pop culture partly because we take any stressful event in the middle of our lives and slap that label on it. One way or another, this is definitely a topic that needs more investigation. But the good news is that even if the U-curve does exist, it doesn't mean that middle-aged people are all miserable.

On average, studies so far have shown it's actually a pretty small decrease in happiness, not the life-altering angst we associate with the stereotype. So don't worry about it too much. Your job-quitting, Ferrari-buying phase might never arrive.

Thanks for watching this episode of SciShow Psych! If you'd like to keep learning about the human mind with us, you can go to youtube.com/scishowpsych and subscribe. [OUTRO ♪].