How Kindness is Contagious

image: (c) Dr David R Hamilton

I’ve written, and I speak a lot, about how we are contagious, although not in the usual sense of the word where we catch the cold from each other, but in how our emotions are contagious.

Social network research shows that if you feel happy, for instance, you not only infect your friends with happiness, but you also infect your friends’ friends and even your friends’ friends’ friends – out to a radius of three social steps. This is partly facilitated through mirror neurons, specialised cells in the brain that mirror our physical expressions of emotion.

But I set out to research this field because I wanted to see if I could find evidence to support the idea that a small group of people with compassion and kindness in their hearts could change the world. I wanted to know, specifically, if kindness is contagious.

To me it is pretty obvious. If someone does something kind for you, you feel better and are more likely to help out someone else. So that person’s kindness has been contagious in that it has infected you. Similarly, each time you do something kind for anyone, whether it’s a family member, friend or a stranger, your kindness is also contagious. Please know that it doesn’t stop with that person.

As you go about the rest of your day, repercussions of your kind behaviour continue to ripple on, just as a pebble dropped in a pond creates waves that lift a lily pad at the other side of the pond.

I believe that kindness is contagious in three ways. The first is that we feel elevated when someone helps us. We’re on the crest of an emotional wave for a short time and from this state we feel inspired to help other people.

Depending upon the situation, we might also feel relieved when someone helps us, especially if the situation we’re in is stressful. This reduces the stress or worry and we feel a surge of relief. Stress and worry often obstruct our real nature, which contains strong undercurrents of compassion and kindness. When stress goes away and is replaced with a feeling of relief, we’re more likely to act on opportunities to help others.

The third way is that when we see someone being kind, something inside tells us that this is what we should be doing and so we are inspired by the observation of another’s kind behaviour. This is called social contagion.

Kindness is natural to us. It’s odd, but much business has traditionally been done based on the mistaken idea that humans are inherently selfish and look out only for themselves. This has played a role in establishing the competition business model and also made it OK to gain at the expense of another’s loss. This, in my opinion, has played a big role in the economic challenges that face us now.

But actually, what’s natural to us is cooperating with each other, working together, and showing heaps of compassion and kindness. Our genetic ancestors survived hundreds of thousands of years because they learned to work together and to help each other. They thrived because they cared when someone was hurt and because they helped each other. We are here today because they learned that the best way to thrive as a species was to be kind.

And we can see the genetic wiring quite clearly today. Oxytocin is a hormone heavily involved in empathy, compassion and kind behaviour. Kindness creates emotional bonds, which elevate oxytocin levels. Studies show that there are 15 variants, or ‘colours’, in just a small section of the oxytocin receptor gene (that’s the gene that produces the sites on the cells that oxytocin binds to). Those with a lighter shade, so to speak, tend to show more kind behaviour, whereas those with a darker shade are less likely to help others. It is evidence like this that confirms, scientifically, that being kind is a natural thing in us, that the tendency has a strong genetic component. We are not wired to be selfish. We are wired to be kind.

Thus, the solution for the world economy is not in more competition – being bigger, better, and stronger than everyone else – but in more cooperation, just like the solutions to many of our own challenges in our lives lies in cooperation. The seeds of the path ahead lie in kindness towards one another because cooperation builds upon kindness. We need to extend our hands to others.

And just how contagious is kindness? Well, just like emotions, a Harvard study found that kindness also affects our friends, our friends’ friends, and our friends’ friends’ friends. Kindness ripples out to a radius of three social steps.

The research, led by Professor Nicholas Christakis, asked volunteers to play a business game known as the ‘Public Goods’ game, where each person has to put money into a public pot to benefit the community. When one person made a larger donation into the public pot it caused some of those in the group to make larger donations in the next round of the game, which they played with different people. The people in that round, observing the larger donation, then went on to raise their donations in the following round. And similarly, those in that round raised their donations in the next round. The effect of one person’s kind behaviour affected the tone of the game for three successive rounds.

So consider this: this is the holiday season, the season where we traditionally show more goodwill towards each other than normal, so with each act of goodwill you show someone, pause for a second and reflect on the fact that your act of kindness will ripple far further than just the environment you’re in.

My experience shows me that when you have this in mind, you’re more likely to show even more goodwill, and more often, because you start to realise that you really can make a difference.

So with this is mind, can a small group of dedicated people with compassion and kindness in their hearts change the world?

What do you think? I think we can!


  1. Scientific Impact of Kindness (1) » Jullba on April 2, 2022 at 2:53 am

    […] 1 Hamilton, D. (2011). David R Hamilton PhD | How Kindness is ContagiousDavid R Hamilton PhD. Retrieved 23 January 2021, from  […]

  2. […] bestselling author and kindness scientist Dr. David R Hamilton explains, it’s actually really […]

  3. ‘Kindness is contagious’ on January 27, 2023 at 11:50 am

    […] to Dr. David Hamilton, when people receive kindness, they feel compelled to do the same thing to others. Hence, people […]