People are at their happiest at the ages of 23 and 69, a study by the Center for Economic Performance at the London School of Economics and Political Science suggests.
The researchers surveyed 23,161 people between 17 and 85.
The findings overthrow the received wisdom that people are happiest when they are young and carefree and get steadily more miserable as they get older.
In fact, people in their mid-50s are the unhappiest.
Hannes Schwandt, a visiting researcher at the LSE who led the research, said, "People in their 50s could learn from the elderly, who generally feel less regret," he said. "They should try not to be frustrated by their unmet expectations because they are probably not feeling much worse than their peers."