Elon Musk says money can't buy happiness. Research shows he's both right and wrong.

• Elon Musk said the adage that money can't buy happiness has some truth to it.
• The SpaceX and Tesla CEO is the richest person in the world.
• Research suggests money can increase happiness, but only up to a point.

Elon Musk wants you to know that the money hasn't made him happy.

"Whoever said 'money can't buy happiness' really knew what they were talking about," Elon Musk wrote in a post on X on Thursday with a sad-face emoji.

The SpaceX and Tesla CEO is by far the richest person in the world. Per the Bloomberg Billionaires Index, he is worth $668 billion. The second-richest person in the world, Larry Page, is worth $285 billion.

Musk's wealth has soared by $49 billion since the start of the year, buoyed by SpaceX's high valuation and news of its merger with his AI startup, XAI.

So, is Musk right or wrong that money can't buy you happiness?

Studies show that money does bring happiness, but there could be a limit for the ultrawealthy.

David Bartram, an associate professor of sociology at the University of Leicester, told Business Insider that while wealth and happiness are linked, "It's very much a matter of 'diminishing returns.'"

"Once you've got a few million, anything extra is meaningless for happiness," he said.

Bartram said for the very wealthy, "happiness is probably best achieved by having a sense that you've done some good in the world, and that you've treated people around you with care and kindness. It's not exactly rocket science."

A 2021 study by Matthew Killingsworth, a senior fellow at the Wharton School at the University of Pennsylvania, found that happiness and feelings of well-being increased in tandem with a person's rising income.

However, the amount of money needed for happiness becomes an exponentially moving goalpost, Killingsworth concluded in a 2024 paper.

While the data he analyzed did not examine what millionaires or billionaires are experiencing, Killingsworth said it was "plausible" that the pattern would continue among the world's wealthiest.

Musk discussed the relationship between happiness and wealth in a recent conversation with Nikhil Kamath on the "People by WTF" podcast.

"Aim to make more than you take. Be a net contributor to society," Musk said in November.

"It's kind of like the pursuit of happiness. You know, if you want to create something valuable financially, you don't pursue that. It's best to actually pursue providing useful products and services. If you do that, then money will come as a natural consequence, as opposed to pursuing money directly," he added.