The sad clown: The deep emotions behind stand-up comedy

In "Spark of Madness," one hour of the eight-part CNN documentary series "The History of Comedy," comics talk openly about their mental struggle and how it fuels their work.

"I despised myself from pretty much close to getting out of the womb," comedian Richard Lewis said in the documentary. "I was always wrong. Let's start with that. When you are always wrong, you seek an audience to disprove that theory."

It's unclear in scientific literature whether this is true for all comedians. Does one need a mental struggle to be funny? Or is it that some comedians better understand these challenges and can speak to them without experiencing the struggle themselves?

What we do know is that analyzing humor is a lot like dissecting a frog, the old joke goes: No one laughs, and the frog dies. Yet in increasing numbers, scientists are trying to understand what motivates the professional jokers to want to make us laugh, even if they can't always do it for themselves.

The research is laughably contradictory.

Legendary psychoanalyst Sigmund Freud theorized that comedians often tell jokes as a kind of relief system from some kind of anxiety.

More recently, an often-quoted study from 1975 (PDF) theorized that humor can leave the comedian with a feeling of control over a situation in which they would otherwise be powerless.

"One can note here the plethora of jokes about doctors, psychiatrists, undertakers, sex and mothers-in-law," study author Samuel James wrote. If a comedian did struggle with their own mental health, the jokes could act like a salve for a physical wound.

That 1975 study focused on 55 full-time comedians who were highly successful. They had national news coverage and had a salary well over six figures. Despite their enormous success, James found, 80% of them had sought some kind of therapy.

The majority of those comedians had a few personality traits in common. They had higher-than-average to well above-average intelligence; other studies have linked high intelligence to depression.

The study participants felt as if they understood themselves fairly well and had good relationships, yet they often felt "misunderstood, picked on or bullied." They were also more likely to be "angry, suspicious and depressed" compared with those outside that profession.

Humor can also decrease social distance between people.

The comics more often reported being close with their mothers but had more distant and disapproving fathers. Other studies have found the opposite parental relationship in comedians.

Mental illness is often linked to suicide, but scientists agree that despite high-profile cases such as Williams', there isn't a disproportionate number of suicides in the profession. However, comedians don't live as long as their less-funny peers, according to a 2014 study titled "Does comedy kill?" It merely adds up numbers but doesn't get at the reasons behind them.

Gordon Claridge, a psychologist who is retired from the University of Oxford, is still gathering data about comedians to better understand their personalities.

He has found that comedians seem to have two competing personality traits: introverted anhedonia (inability to feel pleasure) and extroverted impulsiveness. Although they are similar to actors, who remain extroverted, open and interested in understanding the world around them, comedians have introverted traits that make them asocial and a little emotionally flat. Some also suffer from clinical depression.

That personality split with their impulsive, extroverted tendencies may be behind their funny perspective on the world.

"We found a rather curious set of conditions out there," Claridge said. "Comedy may partly be a form of self-medication, something we don't see at all with other artists."

In the CNN documentary, comedian Patton Oswalt agrees: "A lot of comedians are people that are very introverted, very shy, very sensitive to humiliation. The only way to combat it is to go to the one place where you are stripped bare."

Claridge's study has limitations in that it focused only on male comedians. Other studies contradict his research, finding that there is no more depression among comedians than non-comics.

Claridge has gathered data about female comedians and will investigate whether they will have similar personality traits.

When he has presented his work to comedians, they've said that his findings were obvious from the people they knew on the circuit.

"My dad's humor came from life, and I don't think Dad had a choice," Pryor's daughter Rain Pryor said in the documentary. "You either laugh your way through it, or you die through it."

If comedians truly do have competing personality traits, humor may be their way of forcing their introverted selves to interact.

A study from 2014 looking at comedians and circus clowns found that comics tend to make more negative remarks about themselves compared with other performers.

And despite the perception given by comedians like Woody Allen, they are not typically neurotic, studies show. They score high in creativity and openness, although they tend to display lower conscientious and agreeable behavior than other performers (PDF) and writers, and they tend to be more critical and suspicious. This may give them the distance they need to observe human behavior with a comic eye.

A survey of comedians for a study in 2014 found that some standup artists did it largely for what one comedian in the study said was the "validation via the audience. We are trying to fill a hole." That research concluded that comics have a kind of "paradox of identification."

Claridge believes that, whether they have a personal struggle or are merely good at observing others, comedians all have an interesting story beyond the laughs.

"They all seem to have a hidden depth to their personalities," he said. "Comedy seems to be a way to deal with it, and we all benefit from it."