Are people with kids happier than people without? In the United States, those with and without kids rate their lives about the same, but globally children tend to diminish well-being, said a study Monday.
The results were derived from two major surveys by Gallup that included almost three million people worldwide.
One survey covered nearly 1.8 million Americans from 2008 to 2012 and the other interviewed 1.07 million people from 161 countries between 2006 and 2012.
Participants were asked how close their lives were to being ideal, and what kinds of emotions they felt the day prior. Potential responses included happy, sad, angered, worried or stressed.
Parents reported more ups and downs than non-parents. Those with children at home reported higher levels of all the emotional responses, including happiness and stress, smiling and anger.
But when researchers took into account other attributes that parents tend to have -- higher education, more income, better health and religious faith -- they found similar levels of life satisfaction as reported by non-parents.
On the whole, both US groups rated their lives about a seven on a scale of one to 10.
Adults of all ages with children at home rated their lives 6.82 while the childless came in at 6.84.
When researchers looked solely at people in the prime child-rearing years (age 34-46) they found people with kids rating their lives at 6.84, just higher than those without kids at 6.51.
In the rest of the world, the survey results told a different story: people with kids -- at least those outside the rich English-speaking world -- tended to be less content with their lives.
"Our results for the world as a whole, as well as for Africa, Latin America, the Middle East, and South Asia are consistent with the most common finding in the literature, that those with children have lower life evaluation," said the study.
"The higher the fertility rate, the more likely are people living with children to report lower life evaluation than those who do not."
In poor countries, personal happiness may take a back seat to necessities, like requiring extra bodies to work the farm, the study suggested.
"Because of social norms, or pressure from their own parents and communities, or because of the productive contributions of children, people may have children even when, on a purely personal level, they would rather not do so," it said.
People were asked to rate their lives for the Gallup surveys, and were later asked a series of questions about their income and whether their households had children in them or not.
They were never asked directly whether their kids made them happy, or how having kids or not having kids affected their view of their lives.
Princeton economist and lead author Angus Deaton said the heart of the matter is the ability to choose.
"The take-home message is 'Do what you want to do,'" he told AFP.
"If you think children would make you happy, it's probably true. And if you think they wouldn't, it's probably true, too."
The study appears in the Proceedings of the National Academy of Sciences.