Hey Reader, before we get into the science of how happiness "jumps" from person to person, I have an exciting announcement...🥁

I'll be a speaker at the TEDNext Conference this November in Atlanta, GA! It's a huge honor, and I can't wait to meet the other speakers. The event is November 9-11, and you can learn all about it here.

And now that I think about it, sharing that happy news with you is kind of the perfect lead-in to today's topic. This week, I’m excited to share this newsletter with my longtime friend and collaborator, Dr. Harry Reis. Harry and I have both spent years studying how our connections with others shape our well-being.

And one of the most interesting findings is this:

Happiness is contagious.

When someone close to you feels good, that feeling doesn’t stop with them—it spreads to you and even to people you don’t know.

A classic study by James Fowler and Nicholas Christakis followed thousands of people for 20 years and found that when your friend is happier, you’re about 15% more likely to feel happier yourself. Even when a friend of your friend is happier, you’re 10% more likely to feel happier. And the ripple keeps going—your friend’s friend’s friend’s joy is associated with about a 6% higher likelihood that you’ll feel good, too.

That’s how powerful shared emotions can be.

(Of course, these are correlations—meaning this study found that happiness tends to move together among connected people, but it doesn’t prove one person’s mood causes another’s.)

Why does this happen?

One reason is that we naturally mirror each other. When you see someone laughing, you might start smiling without even realizing it. These tiny moments build over time, nudging your mood in a more positive direction.

But there’s something deeper, too. When you share good news with someone, the way they respond makes all the difference. If they react with genuine enthusiasm and support—what Harry Reis and his former student Shelly Gable call “capitalizing”—it can feel like your joy is doubling in real time.

Studies have found that people who often share happy moments with their partners or friends feel closer, more satisfied in their relationships, and happier overall. They even feel an extra jolt of happiness about the thing that made them happy in the first place.

This is a good reminder:

If you want more joy in your life, look for ways to connect with people who lift you up—and celebrate their good news right alongside them.

Happiness Hacks

Here are a few simple ways to practice “capitalizing”—sharing good news and responding to them with warmth and curiosity:

Start a Daily Joy Share

Once a day, tell someone about one good thing that happened—big or small. It could be as simple as, “I finally finished that project” or “I had the best cup of coffee.” Invite them to share something good, too.

Celebrate Without Hesitation

When someone you care about shares good news, lean in. Ask questions like, “What was the best part?” or “How did that feel?” Your enthusiasm shows them that their success and happiness matter.

Send a Spontaneous Joy Message

Try texting a friend or family member just to say, “This made me smile today, and I thought of you.” It’s a small gesture that can brighten both your days.

Be a Joy Receiver

Next time someone shares something positive, set the intention to be fully present. Smile, listen carefully, and let yourself feel happy with them.

Reflect on What Holds You Back

If you notice yourself hesitating to share something you’re proud of, pause and ask why. Are you worried it sounds like bragging or won’t be received well? (Honestly, I had that worry before announcing my TED talk earlier.) Remind yourself that shared joy helps everyone feel more connected.

Sharing positive moments isn’t just a nice thing to do—it’s one of the simplest, most powerful ways to deepen your relationships and feel happier yourself.

Until next time,

Sonja

References

Fowler, J. H., & Christakis, N. A. (2008). Dynamic spread of happiness in a large social network. British Medical Journal, 337, a2338.

Gable, S. L., Reis, H. T., Impett, E. A., & Asher, E. R. (2004). What do you do when things go right? Journal of Personality and Social Psychology, 87(2), 228–245.