Product of the brain

Even laughter, with all of its cultural associations, is the product of specialized networks in the brain.

Willy loved his mother deeply, and he grieved heavily when he heard the news of her passing.

When the day of her funeral came around, he performed every solemnity that you would expect. He donned a crisp black suit, spoke lovingly at the funeral service, and mourned with his family at the open grave where his mother was to be buried. It wasn’t until his mother’s casket was being lowered into the earth that Willy began to laugh.

At first it was only a hushed snicker, but it soon became a giggle. He clasped his hand to his mouth, trying to smother his mirth, but to no avail – he soon exploded with a hearty laugh. He kept laughing until he was doubled over and, in that bent position, he desperately tried to stagger away. The other attendees could only watch, mouths agape.

Willy had experienced an outburst of compulsive laughter. Cases are rare in the medical literature, but what we know is that compulsive laughter is almost always associated with abnormal behavior in the limbic system, a cluster of structures involved in producing emotions.

That said, it’s not exactly clear what caused Willy’s limbic system to malfunction so strikingly. Could it have been caused by the shock of his mother’s death? To answer that question, we need to explore what this strange paroxysm of sound – laughter – is actually for.

Some evolutionary psychologists speculate that laughter first developed in our ancestors as a form of communication. They suggest that laughter might have served to alert others in a group that a potential threat was actually a false alarm. The laugh signals to everyone simultaneously that there’s really nothing to worry about – we can all relax.

Of course, this theory doesn’t account for all the nuanced functions of laughter in today’s society. But perhaps once this primordial laughter structure was in place, it was co-opted for other functions. This is a very common evolutionary strategy. Feathers, for example, were originally developed in birds for insulation; only later were they adapted for use in flying.

So maybe laughter is like the feather. It originally developed for something simple, like helping the group to relax after encountering a potential danger in the wild. Later on, it evolved to trigger relaxation when faced with other stresses, too. That would explain why so many jokes are about sensitive topics, like sex and death.

And it might also explain poor Willy’s outburst. Perhaps his uncontrollable laughter was an exaggerated response from his “false alarm” system in an attempt to relax him after a traumatic experience.