A homely study published in 1989 may have removed some of the mystery about Christmas in the United States of America.
“Inferences about homeowners’ sociability: Impact of christmas decorations and other cues,” Carol M. Werner, Sonja Peterson-Lewis, and Barbara B. Brown, Journal of Environmental Psychology, vol. 9, no. 4, December 1989, pp. 279-296. (Thanks to Ted Schark for bringing this to our attention.) The authors, at the University of Utah and at Temple University, explain:
Previous research suggests that U.S. residents may use holiday decorations on their home’s exterior to communicate friendliness and cohesiveness with neighbors. In the present research, we examine whether strangers (naive raters) can accurately identify the more friendly residents, and what aspects of the homes’ exteriors contribute to their impressions…. Participants rated residents based only on photographs of their home and front yard.
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.