Why kindness is good for you: what research says

You have probably noticed it yourself. You help a neighbour with a heavy box, let someone go ahead of you in a queue, or send a friend a message at the right moment, and for a little while you feel better. Lighter, somehow.

The idea that kindness is good for the giver is old. It appears in religious traditions, in philosophy and in your grandmother’s advice. In the last two decades psychologists have tried to test it properly, with surveys, experiments and large meta-analyses.

The short answer is that the idea holds up. The longer, more useful answer is that the effect is real but modest, that some famous findings shrank when tested again at scale, and that how you are kind seems to matter. This guide walks through what the research says, honestly, and what it means for your day.

What researchers mean by kindness

In the research literature, kindness usually goes by the name prosocial behaviour: actions meant to benefit someone else. That covers a wide range, from donating money and volunteering to holding a door, giving a compliment or listening to a friend who is struggling.

Studies measure it in two broad ways. Some simply ask people how often they help others and compare that with how happy or healthy they are. Others are experiments: people are randomly assigned to do kind acts or not, and researchers compare how they feel afterward. The experiments are more convincing about cause and effect, because random assignment rules out the explanation that happy people are simply more likely to help.

Both kinds of evidence matter, and they point in the same direction.

The money experiments

The study that put kindness research on the map was published in Science in 2008 by Elizabeth Dunn, Lara Aknin and Michael Norton. It had three parts.

First, a survey of 632 Americans asked how they spent their money each month. People who spent more on gifts for others and on charity reported being happier. How much they spent on themselves was not linked to happiness.

Second, the team followed 16 employees at a Boston company before and after they received a profit-sharing bonus. Those who spent more of the bonus on others reported greater happiness afterward. The size of the bonus did not predict happiness; as one of the researchers told the Harvard Gazette, “All that mattered was the percent spent on other people.”

Third, and most persuasive, was an experiment. Students received an envelope with either $5 or $20 and were told to spend it by the end of the day, either on themselves or on someone else. That evening, those who had spent it on others were happier. The amount did not matter.

Does it hold across cultures?

A natural worry is that this is a finding about comfortable North American students. In 2013 Aknin and colleagues tested it more widely. Survey data from 136 countries showed that spending on others was associated with greater happiness in both poor and rich countries. Experiments in Canada, Uganda and India found that simply recalling a time you spent money on someone else raised happiness. In Canada and South Africa, people who bought items for charity reported more positive feelings than those who bought the same items for themselves.

What happened when it was tested again

Science works best when exciting findings are checked with bigger samples. In 2020, the original researchers did exactly that, in a preregistered replication published in the Journal of Personality and Social Psychology. Earlier studies had typically used fewer than 100 people per group; this one used thousands.

The results were mixed, and the authors reported them openly. In an experiment with 712 students, those who bought something for a stranger in need reported more momentary happiness than those who bought for themselves. In a study of 1,950 adults asked to recall a past purchase, there was no significant difference. In a third study of 5,199 people, recalling spending on others did lead to more happiness, but the differences were small.

That is the honest state of the money research: a real effect, smaller than the early headlines suggested, and not something that shows up every time.

The kindness meta-analyses

Beyond money, two large reviews give the clearest picture.

Acts of kindness: a small-to-medium boost

In 2018, Oliver Scott Curry and colleagues pooled every experiment they could find in which people were asked to perform acts of kindness and their wellbeing was measured. Twenty-seven studies, with 4,045 participants in total, met their criteria.

The overall effect on the kind person’s wellbeing was small to medium (a standardised effect of about 0.28). It did not depend on sex, age, the type of kindness or how wellbeing was measured, and the authors found no sign of publication bias.

To put that in perspective: an effect of that size means that, on average, people who practised kindness ended up somewhat happier than those who did not, with a lot of overlap between the groups. Kindness will not transform a hard season of life on its own. But as a free, low-risk habit with benefits for other people too, it is a good deal.

The bigger picture: modest, with interesting patterns

In 2020 Bryant Hui and colleagues published an even broader meta-analysis in Psychological Bulletin, covering 201 studies and nearly 200,000 people. They looked at the link between prosocial behaviour and wellbeing of all kinds.

The average link was modest (a correlation of 0.13). But the averages hid some useful patterns:

• The link was stronger for eudaimonic wellbeing, the sense of meaning, purpose and personal growth, than for pleasure and mood alone.
• Informal helping, such as everyday acts for neighbours, friends and strangers, was linked to more wellbeing benefits than formal helping, such as organised volunteering.
• Younger givers showed stronger links on most wellbeing outcomes, while older and retired givers showed a link mainly with better physical health.
• Studies that were better designed and specifically built to test this question found stronger links.

Most of the studies in this review were correlational, so they cannot fully separate cause from effect. Kindness may make people happier, and happier people may also find it easier to be kind. The experimental evidence above suggests at least part of the arrow points from kindness to wellbeing.

Does it matter who you are kind to?

In a 2019 study, Lee Rowland and Oliver Scott Curry asked 683 people to perform kind acts for seven days. Some were kind to people close to them, some to acquaintances, some to themselves, and some just observed kindness. A control group did nothing special.

All the kindness groups became happier over the week, and the size of the boost was similar across them. People who did more kind acts tended to see larger increases in happiness.

Two gentle lessons follow. You do not need to wait for a dramatic opportunity or a stranger in need; small kindnesses to people already in your life count. And kindness toward yourself appears to belong on the list, too.

Why might kindness help the giver?

Researchers have several overlapping explanations, and the evidence for each is still developing.

Kindness connects you to other people, and connection is one of the strongest predictors of wellbeing we know about (our guide to loneliness and health covers that evidence). It also gives you a sense of competence and meaning: you made a small difference, and you can see it. And it shifts attention away from your own worries for a moment, which can be a relief in itself.

The link with meaning-based wellbeing in the Hui review fits this picture. Kindness may feel good, but it may matter even more because it helps life feel worthwhile.

How to make kindness count

The research suggests a few practical principles. These are reasonable inferences from the findings above, not strict rules.

Keep it small and frequent. Everyday, informal kindness showed the strongest links with wellbeing, and doing more kind acts went with larger gains. A daily habit of small kindnesses is more realistic than occasional grand gestures.

Make it voluntary. Kindness that feels like an obligation or a performance is unlikely to feel the same. If a particular act would leave you resentful or depleted, choose a different one. Being kind does not mean ignoring your own limits.

Notice the effect. You do not have to keep a diary, but pausing for a moment after a kind act to notice how it landed, for the other person and for you, helps the experience register.

Pay attention. Some of the most valuable kindness costs nothing: giving someone your full attention when they talk. If you want to build that skill, see our practice on how to listen well.

Include yourself. In the seven-day study, self-kindness helped as much as kindness to others. Treating yourself with the same patience you would show a friend is part of the same habit.

Kindness as a way of living, not a technique

It would be easy to turn this research into a productivity tip: do three kind acts a day for a measurable happiness boost. That misses something. The people in these studies were happier partly because they were connected, useful and engaged with others, not because they had found a trick.

Philosophers from the Stoics onward have treated kindness as part of a good life rather than a route to one. In the opening of Book 2 of his Meditations, Marcus Aurelius reminds himself that people are made to work together, like hands or feet. If that idea interests you, our guide to Stoicism for everyday life explores it further. The science adds a modest, encouraging footnote: living that way also tends to feel good.

You do not need a plan or a budget. You need one small opening today, and the willingness to take it.