SAN FRANCISCO (NewsNation Now) — Many say the unofficial start to Christmas is the day after Thanksgiving. But according to experts, putting up decorations early may make you happier and friendlier, so you might want to consider pulling out your garlands and gigantic blowups down from the attic a bit sooner.

New research in the Journal of Environmental Psychology finds that 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, at least mentally. They also help boost dopamine, the feel-good hormone.

So if you’re feeling like a grinch this season, consider putting up your Christmas tree early.

NewsNation affiliate KRON contributed to this report.