You’re similar to me, so have my vote

Research into romantic attraction has shown that we're often drawn to people who are similar to ourselves. Now Gian Caprara and colleagues have shown the same principle applies to our voting habits.

Over 1,500 Italian voters rated their own personality and the personality of the then President Silvio Berlusconi or his more left-wing rival Romano Prodi, using 25 adjectives that map onto what psychologists call the 'Big Five' personality traits.

Participants who had previously voted for Berlusconi tended to rate both themselves and him as being high in energy/extraversion, whereas centre-left Prodi voters, although they too saw Berlusconi as energetic and outgoing, did not rate themselves in this way. Centre-left voters, however, saw both themselves and Prodi as being high in friendliness.

In a second study, 6,094 American voters rated their own personality and the personality of John Kerry and George W Bush. This time Kerry was unanimously viewed as scoring high in openness – a trait that Kerry voters, but not Bush voters, also saw in themselves. Bush was seen by most as loyal and sincere, attributes that his voters also saw in themselves.

So in both Italy and America there was general agreement among voters in the personality traits of the political candidates. Crucially, it appeared that if a voter considered that they shared a candidate's traits, then they tended to vote for them.

The trouble so far is that the direction of causality has not been determined. People could be voting for politicians who they see as being like themselves, or they could be voting for a given politician and only afterwards forming the perception that that person is just like themselves. To test this, 120 American voters rated their own character and that of Bush and Kerry one week prior to the November 2004 Presidential election. People who saw themselves as similar to Kerry and dissimilar to Bush tended to go on to vote for Kerry (the reverse also held, with people who saw themselves as similar to Bush going on to vote for him).

"These findings…further attest to the role that personal characteristics of both voters and candidates play in orienting political preference," the researchers said.

Further reading

Caprara, G.V, Vecchione, M., Barbaranelli, C. & Fraley, R.C. (2007). When likeness goes with liking: The case of political preference. Political Psychology, 28, 609-632.