Conservatives and liberals don’t just differ when it comes to politics, they may also make different purchases at the grocery store, according to new research published in Psychological Science, a journal of the Association for Psychological Science.

Psychological research has shown that conservatives and liberals differ on basic personality traits such as conscientiousness, tolerance for uncertainty, and openness to new experience. Researcher Vishal Singh of New York University Stern School of Business and colleagues hypothesized that the conservative tendency to prefer tradition and convention would be reflected in conservatives’ purchasing behavior, leading them to choose established name-brand products over generic brands or new products.

The researchers analyzed weekly sales data from over 1,800 supermarkets in counties across the United States, spanning the years from 2001 to 2006. Using data on voting history and religiosity — factors that are independently correlated with conservative values — they were able to determine the level of conservatism in each county.

After accounting for factors such as income and education, the researchers found that the market share for a wide variety of generic products was lower in more conservative counties than in more liberal counties. Similarly, uptake of newly launched products was systematically lower in more conservative counties. These data suggest that conservative ideology may be associated with reliance on established national brands.

“These tendencies are consistent with traits typically associated with conservatism, such as aversion to risk, skepticism about new experiences, and a general preference for tradition, convention, and the status quo,” Singh and colleagues write.

According to the researchers, this research provides the first evidence for a relationship between political affiliation and buying behavior, suggesting that ideological differences are reflected in daily behavior, even at the unconscious level.

Along with Singh, authors include Romana Khan of the Graduate School of Business at Ozyegin University and Kanishka Misra of the Stephen M. Ross School of Business at the University of Michigan.