People make systematic judgment errors by assigning their own political views to attractive or competent-looking candidates, according to a study published this June in Political Psychology.

Candidates who are perceived as competent, attractive, likable, or nonthreatening, based on their facial images, tend to win more votes in parliamentary, presidential, and subnational elections. This raises questions about the validity of using appearance to make voting decisions.

Research shows that within milliseconds the human brain is able to interpret facial expressions and provide judgments about another person. Furthermore, it shows that this can have a positive influence on voting, improving a person’s ability to predict whether a political candidate is left or right-wing above chance level (55 to 62%). However, one problem with face-based inferences is that they are open to bias, and observers tend to favor their visual impressions whilst ignoring more accurate objective information.

The study, by Michael Herrmann and Susumu Shikano of the University of Konstanz, tested whether people ascribe their own political views to political candidates’ who have more attractive and competent-looking faces (rated by a separate group of 173 participants). 2 experiments were conducted in which the images of politically left-wing and right-wing faces were judged as to whether the person displayed held ideologically left-wing or right-wing views. For Experiment 1, 164 participants judged the photos of the faces of student candidates for a university election; and for Experiment 2, 286 participants judged the photos of faces of professional politicians (Experiment 2). They also completed a short questionnaire on their political preferences.

The results revealed that when judging non-professional politicians’ (Experiment 1), overall predictions were better than chance (60%), but when facing attractive or unattractive-looking candidates, both left-wing and right-wing participants were effected by up 10% in their ability to predict the ideological orientations correctly.

When judging professional politicians (Experiment 2), predictions were also better than chance (55%), but the difference in correct prediction rates amounted to more than 10%, if candidates differed strongly in their facial competence. Furthermore, this had the effect of making right-wing participants become less accurate and left-wing participants become more accurate.

The findings suggest that using the visual appearance of faces can impair a person’s ability to visually identify the candidate who best represents their views, making them more likely to assign their own ideological orientations to the candidate. They also suggest that appearing competent is more important in a professional political environment, and that good looks may help extremist candidates in presenting themselves as more moderate.