In every election cycle, politicians on both sides of the aisle are accused of practicing ‘dirty politics.’ Neither side is immune from these charges but research from psychological science suggests that we may subconsciously associate our notions of ‘clean’ and ‘dirty’ with specific political ideologies.

In a research article published in Psychological Science, a journal of the Association for Psychological Science, researchers Erik Helzer and David Pizarro of Cornell University found that people who are reminded of physical purity report being more politically conservative and make harsher moral judgments regarding sexual behavior.

In the first experiment, participants were asked to complete a questionnaire on their political attitudes. To do so, they had to either step over to a hand-sanitizer dispenser placed at one end of a hallway or walk down an empty hallway. Results showed that people who were exposed to reminders of cleanliness (the hand-sanitizer dispenser) reported a less liberal and more conservative political orientation than people who received no such reminders.

In the second experiment, before being asked to rate their moral approval of various behaviors, some volunteers were exposed to a sign that promoted the use of hand wipes to help keep lab space clean. Those who were reminded of physical purity rendered harsher judgments of sexual acts than the control group.

Helzer and Pizarro note that these findings, when combined with previous research, suggest a two-way link between conservatism and concerns for moral purity. The researchers surmise that political orientation (identifying as more conservative or more liberal) may be shaped, at least in part, by the strength of a person’s motivation to avoid physical contamination. People who try to avoid such contamination are more likely to be vigilant in seeking out threats to purity, which ultimately reinforces a politically conservative worldview.

The researchers emphasize the fact that the effects in these two studies were the result of subtle environmental cues. It’s possible then, that everyday reminders of cleanliness in public places – such as signs in restaurant bathrooms urging employees to wash their hands before returning to work – may have unintended effects on people’s social attitudes.

So here’s a dirty trick, don’t display your cleaning products around unless you want to nudge your friends to the right.