TORONTO -- While it’s often said that "life begins at 40," it appears that unhappiness is not far behind with 47 earning the distinction of the age of peak middle-age misery.

According to a new study published by the National Bureau of Economic Research, there is a U-shaped “happiness curve” over the course of a person’s lifetime that bottoms out at 47.2 years of age in the developed world and 48.2 years of age in developing nations.

“The curve’s trajectory holds true in countries where the median wage is high and where it is not and where people tend to live longer and where they don’t,” Dartmouth College Professor David Blanchflower, the study’s author and a former policy maker for the Bank of England, wrote in the paper.

To measure the relationship between well-being and age, Blanchflower examined data across 132 countries, including 95 developing and 37 developed nations.

He said he found the same U-shaped pattern when he controlled for gender, education, marital and labour force status, the year the data was collected, and when he didn’t apply those controls at all.

“The happiness curve is everywhere,” he wrote.

Blanchflower said there were about 15 different measures of unhappiness he considered for the study, including pain, phobia, despair, loneliness, being under stress, and not being able to sleep.

Despite the varying external factors in people’s lives, Blanchflower said he was surprised to see a general pattern emerge for respondents in all of these different countries.

“It’s true for people who are single. It’s true for people who have got children, who haven’t got children. For men, it’s true for women,” he told during an interview on Wednesday.

What’s more, Blanchflower points to an earlier study from 2012 that revealed a similar U shape exists among chimpanzees and orangutans. That study assessed the “cheerfulness” of 508 great apes and found a similar dip during their middle age.

“The results imply that human well-being’s curved shape is not uniquely human and that, although it may be partly explained by aspects of human life and society, its origins may lie partly in the biology we share with great apes,” he said.

Blanchflower suggested there may be something “deep in the genes” that contributes to this well-being arc in a person’s life cycle.

The author did acknowledge, however, that certain pressures that arise when a person reaches middle age, such as their children moving out or where they are in their careers, undoubtedly affects their well-being.

“Eventually, I think what happens is people’s expectations get real. You decided you wanted to be the Prime Minister of Canada and that was your ambition when you were 25… 35, you’re still struggling, 45 you go ‘OK, I’m going to do something else,’” Blanchflower said.

Blanchflower said the important thing to take away from the study is that “life gets better” after the peak.

“If you’re in a midlife crisis, just understand that lots of other people are as well,” he said. “The other one is don’t be alone. It says that in the data that sharing things, dining with your neighbours, talking to your family, spending time with your family, letting people come and help you because eventually it will get better.”