The Science of Gratitude: How Being Thankful Makes Us Happier and Healthier

Gratitude is a powerful emotion that has been shown to have a number of benefits for our physical and mental health. Heres what the science says about gratitude and how you can incorporate more of it into your life.

Thanksgiving is a time for giving thanks, and it turns out that humans have been doing it for a long, long time. As more researchers dig into the science of gratitude, they've found that the feeling likely played a key role in helping our ancestors band together and survive.

How We Got Grateful

Humans are social animals. That's how we've lasted so long; not by being the biggest or the strongest, but by figuring out how to work together. A key part of building relationships is the idea of reciprocity: "If you like me and do nice things for me, then I like you and do nice things for you," said Michael Tomasello, a developmental psychologist at Duke University.

The animal kingdom has some parallel give-and-take behaviors, said Malini Suchak, an animal behavior researcher at Canisius University. In experiments with capuchin monkeys and chimpanzees, Suchak found that the primates became more willing to help out a partner if that individual had helped them in the past.

Some scientists think the feeling of gratitude evolved to keep the helping exchanges going. In other words, if you were helped, you'd feel like you should repay the debt with a good deed in return, said Jenae Nelson, who researches gratitude at Baylor and Harvard universities.

How We Stayed Grateful

Thousands of years later, gratitude has taken root in humans. Studies have found that gratitude may show up in a few spots in our genes and brains — including ones linked to social bonding, feeling reward, and seeing other people's points of view. And the feeling emerges early on: Children as young as 2 and 3 demonstrate they want to return favors, said Amrisha Vaish, who studies moral development at the University of Virginia. At age 4, children also show a tendency to "pay it forward," she added.

In a study, Vaish found that when kids got help completing a task — in this case, finding a key to unlock a box of stickers — they were more likely to share their sticker reward with a new person. It's that kind of behavior that shows gratitude is more than a simple exchange, Schnitker said. It can make us more generous with other people in general — even if they didn't help us first.

Gratitude Might Be Good for You, Too

A 2016 study found that people who wrote letters of gratitude reported better mental health and saw changes in their brain activity — even months down the line. But Nelson pointed out that recognizing the giver, not just the gift, is key.

So, if Thanksgiving has you in a mood for gratitude, she suggested focusing on thanking the people in your life, rather than just making "gratitude lists" of the stuff you have. This is more in line with why the feeling evolved in the first place, she said.

"It's not just about stuff and materialism," Nelson said. "It's about relationships, and the things that people do for you, and then the things that you can in turn do back for other people."