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

Elon Musk is the world's richest person.

Fabrice COFFRINI / AFP via Getty Images

• 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...