What Laughter Actually Does

One of the famous claims made for laughter stands up well under testing. Several of the others were never really tested at all, and it is worth knowing which is which.

Laughter therapy, sometimes called humour therapy, is the deliberate use of humour to improve how a person feels. Hospitals run programmes. The claims attached to it have grown enormous, and that is a pity, because the modest true thing underneath is genuinely interesting and gets buried under the rest.
The claim that holds
Robin Dunbar and colleagues ran a series of studies in which people watched either comedy or neutral material and then had their pain threshold measured. Threshold rose after genuine, helpless, breathless laughter, and it did not rise after material that people found pleasant but did not actually laugh at.
That distinction is the whole finding. The active ingredient appears to be the physical exertion of laughing, the repeated forced exhalation, which is the kind of effort that triggers endorphin release much as other exertion does. Polite social laughter does not involve that exertion, and it does not produce the effect.
This also explains why laughter is so relentlessly social. Laughing is many times more likely in company than alone, and the pain threshold that rises is a rough measure of endorphin activity, which is the same system implicated in social bonding across primates. Shared helpless laughter is closer to grooming than to medicine.
The claims that do not hold
Ten to fifteen minutes of laughter burns forty calories. This traces to a single small laboratory study of energy expenditure while people watched comedy. Forty calories is a few almonds. It is a charming fact and it is not a plan.
Laughing releases endorphins that outdo an equivalent dose of morphine. Nobody ever measured any such thing. The sentence sets a hormone against a drug in units that do not exist, and it has survived for decades purely because it startles.
It protects against heart disease, builds immunity, and lowers the blood sugar spike after a meal. Each of these rests on a small study measuring a marker, not on any study showing fewer heart attacks or fewer illnesses. A marker moving is where research starts, not where advice starts.
What to do with all that
Nothing medical. If something is wrong, the person to talk to is a doctor, and no amount of comedy substitutes for that.
What the evidence does support is smaller and easier. Laughing properly, with other people, for long enough to lose your breath, makes the next hour more bearable and the people you did it with feel closer. That is not a miracle cure. It is a decent reason to spend an evening with the friends who make you laugh like that, which very few of us schedule and most of us miss.

















