The sweet scent of the narcissus plant wafts upstairs to me just like the lingering memory of my uphill neighbors, an always upbeat Irish couple in their early eighties. Stopping off on their daily walk, they knocked on my door early this morning to deliver the plant, their holiday gift, knowing I would be up and writing. When I first moved to Sausalito I sent an invitation in a package of filbert and raspberry cookies (my mother’s recipe) to 30 of my closest neighbors. I asked them to drop by for a brief “neighborhood safety” talk from Alicia, our local policewoman. And, of course, I told them I’d have coffee, wine and homemade deserts on the table for us to snack together.

One minute it’s quiet on the evening of the get together. Then, to my surprise everyone turned up. Many arrived on the dot of 7:00 pm. Some recognized each other but didn’t know names. By 7:15 our living room, dining room and kitchen were filled with neighbors involved in convivial conversation. At 7:30 pm I invited them all into the living room to hear our Sausalito policewoman offer eight tips on how we can help each other be safer in our neighborhood – and five specific ways the local police can help us. How fascinating to find that night that within minutes of my home lived a retired FBI agent, an eco-lodge designer, a fisherman and a hedge fund manager and a digital designer.

That began a tradition, over the years, of casual, round robin get-togethers at each other’s homes, a shared email and phone list and the habit of referring good plumbers, tree trimmers (a big deal with our views of the bay at stake) and other trusted services. Now, years later, there are over 100 neighbors (and Alicia and the city manager) on our private neighborhood list. Yet, without discussing it, we’ve tacitly agreed that we don’t use it to promote our businesses or to endorse local candidates.

It is not just the fragrance of the narcissus plant that makes me smile this holiday morning but the synchronicity in opening an email to right after I hugged my Irish neighbors goodbye. That email had some unexpected results from a study by Nicholas A. Christakis and James H. Fowler about the extraordinary contagion of happiness. It turns out that:
• When one person is happy, the effect is felt up to three degrees away. Your happiness is connected to the happiness of your friends, their friends’ friends, and their friends’ friends’ friends
• Your friendship with people who are often happy boosts your happiness – and that of people around you.
• Each new happy friend you gain increases your probability of being happy by about 9%.
• Happiness is more viral than unhappiness. Encountering people who feel happy is more uplifting and spreads farther than being around people who are unhappy – your mood goes down less and you are less likely to transmit that down feeling to others you encounter.
• People at the center of a social network tend to be happier than others in their group or the situation. At that holiday party, the person who is enjoying conversations with many people feels more upbeat than those who are talking with fewer people. Fowler suggests, “We think the reason why is because those in the center are more susceptible to the waves of happiness that spread throughout the network.”

• Oddly, when a person becomes happy:
– A friend living close by has a 25 percent higher chance of becoming happier themselves.
– A spouse has only an 8 percent increased chance of happiness.
– Next-door neighbors have a whopping 34 percent increased chance.
For women especially this is a vital alert (it is never too late to host a party or sparkle with others at one) during these emotion-laden holiday times. That’s because, more than men, we women ruminate about regrets, hurts and losses.

So savor each day, spreading joy to the world, bathing in the waves of happiness that sometimes ripple back and around you, knowing your happiness may reach others you do not even know.