SAN FRANCISCO (KRON) — If you already started decorating for Christmas, consider yourself a happy and friendly person.

Research listed in the Journal of Environmental Psychology finds people who put up their Christmas decorations early tend to be happier and friendlier.

“The results support the idea that residents can use their home’s exterior to communicate attachment and possibly to integrate themselves into a neighborhood’s social activities,” researchers wrote.

Psychologists say Christmas decorations are nostalgic and bring people back to simpler and happier times. They say it also helps boost dopamine.

“It does create that neurological shift that can produce happiness,” psychologist Deborah Serani told TODAY. “I think anything that takes us out of our normal habituation, the normal day in, day out … signals our senses, and then our senses measure if it’s pleasing or not.”

The only potential downside to decorating early is you’ll need to take care that your Christmas tree lives long enough to make it to the big day. If properly cared for, Good Housekeeping estimates a healthy Christmas tree will last about five weeks on average. But if you want the Christmas spirit to last longer than that, a fake tree should do the trick.