Why Do Babies Laugh?

Exploring the Research on Babies and Laughter

Humour is a subjective quality amongst ourselves. Whether it is the sophisticated but witty philosopher’s banter, dumb humour, or the tantalizing recesses of dark comedy, we can appreciate a good laugh every now and then.

Babies aren’t good at being subtle when they’re amused or scared. Sometimes they make wildly animated faces when you provide them peek-a-boo, and other times, they just start crying for no reason.

But why do babies laugh?

Do they truly find their parents funny or is this some sort of automatic cognitive reflex? Perhaps laughing itself will help with their overall brain development, including their ability to socialize and/or laugh with others in the future.

According to Dr. Gina Mireault, a leading childhood researcher and developmental psychologist, children start laughing well before they are 4 months old. (For context, a lot of Dr. Mireault’s research surrounds babies and their laughter.)

In 2017, she wanted to investigate the earliest sense of humour recognition in children to determine if laughing was a learned skill or innate behaviour.

She primarily used short videos of 53 baby test subjects. In one excerpt of the videos used in the study, a baby would sit with their parent or guardian on one side, while the experimenter sat on the other side.

The experimenter would put on a clown nose.

While it sounds absurd, the experimenter would rhythmically press their finger against their clown nose, making a high-pitched beep. The parents would be instructed ahead of time to laugh at the researcher.

Sometimes, the infants would be confused and fervently glance back and forth between guardian and researcher. After 10 of these beeps were made, the baby would start chuckling, but still look confused, continuously darting cautious glances on each adult.

After about 45 seconds, the researcher would stop making beeping sounds, and the guardian would watch the researcher emotionlessly. The researcher would make more beep noises than before. After about 4–5 instances of these beeps, the baby would start to smile, breaking out into laughter.

Then, the baby would look back at their guardian and stop smiling.

This study was a curious exercise into what contexts children laughed in.

Further studies were replicated by Dr. Mireault, where she examined 4-month olds, 5-month olds, and 6-month olds. Since her research gained considerable funding, the version of her study that had 4-month olds included participants who were equipped with heart monitors. She wanted to assess their physiological response as well.

According to the findings of her studies overall, the babies generally learned to laugh before they could speak or crawl. When the parents laughed, the babies laughed even harder. Even when the parents behaved neutrally after laughing, the infants still laughed on their own, but not before looking for confirmation from their guardians.

When the parents were neutral with the 4-month olds, the children’s heart rates also decelerated, suggesting that the parents helped them elicit pleasurable emotions like joy, which allowed them to maintain their social engagement and attentional span in emotional scenarios, including comedic situations.

Therefore, babies laugh because they can physiologically recognize humour before 4-months and can learn to independently recognize humour after 5-months.