It's official - as the song says, we really can spread a little happiness as we go by! Research from Harvard University has found that one person's happiness has a chain reaction.
Scientists who studied 5000 people over 20 years discovered that your good news can spread from friends to friends of friends, and beyond - even positively affecting people that you've never met.
In fact, just one happy event can give a happiness glow that lasts for up to a year. Here's how to keep those moments going.
Phone a friend. Don't keep good news to yourself. A happy event like a birth or an engagement is also a great excuse to get back in touch with people you haven't seen for years.
Extend your social networks. Sites like Facebook are making it easier than it's even been to connect with people you don't know through shared interests or concerns.
Think local. Use your corner shop, go along to that meeting at the town hall or get involved with a local charity.
Take a tip from the Scouts and try to do one good deed a day, whether it's picking up a bit of litter or having a cup of tea with an elderly neighbour.
Share those little things that make you happy, whether it's seeing the daffodils in bloom, talking about a film or TV programme that you've enjoyed, or baking your favourite cupcakes!