A study from the University of Glamorgan found that age 52 is when “both men and women begin to suffer a sharp decline in their sense of humour and get increasingly grumpy.”

Also, humor and the laughing drops quite a bit from being an infant to being a teenager and then drops again after having kids:

The study found that while an infant can laugh aloud as many as 300 times every day, life rapidly becomes far less fun.

As Harry Enfield’s Kevin and Perry so deftly depicted, things soon change. While teenagers are the age group most likely to laugh at other people’s misfortunes, they laugh on average just six times a day.

Things get even bleaker in what should be the relatively carefree twenties, when we laugh four times a day.

This rises to five times a day throughout the thirties, when having children is cited as a major factor in restoring a sense of humour.

By the time we reach 50, Brits are laughing just three times a day, while the average 60-year-old manages a hearty guffaw just 2.5 times in the same period.

Just five or less laughs a day throughout all of adulthood? Assuming that this can be somewhat generalizable to Americans, it suggests that we need to laugh more.