It is never too early to put up Christmas decorations, according to a study published in the Journal of Environmental Psychology.

The main reason? It shows friendliness. 

The study took into consideration homes with and without Christmas decorations and concluded that there were more positive social interactions in homes with Christmas decorations. 

"As expected, a main effect for the decorated factor indicated that raters used Christmas decorations as a cue that the residents were friendly and cohesive. Decoration interacted with sociability in a complex but interpretable way," the study said. "When Christmas decorations were present, raters actually attributed greater sociability to the nonsociable residents, citing a more open appearance as the basis for their judgments."

Or as psychotherapist Amy Morin told ABC News, “When you’re putting up decorations, you’re thinking of happier times, times with family and friends and family traditions you engaged in."