The remarkable Hannah, our researcher on this series, dug into the findings of decades of studies about interpersonal attraction - the platonic kind, and shares variations of the most established theory here: similarity.
Since the 1950s, social scientific research has provided considerable support for the idea that people are attracted to those similar to themselves.
Researchers from a variety of fields such as marketing, political science, social psychology, and sociology have contributed to and gleaned information from empirical tests of similarity/attraction theory.
The idea that people tend to like those similar to themselves is by no means definitive however. As Newcomb pointed out, this particular "law" of human behaviour has limited usefulness because it is indiscriminate, and far too broad. Although two individuals sharing a passion for obscure (deeply underrated) music hall classics may be likely to hit it off, it is less likely that those in possession of a similar length of big toe, or National Insurance Number will be attracted in quite the same manner.
Nevertheless, there is quite a body of evidence to suggest that people will like those who possess attitudes similar to their own, but also, that people perceive themselves as being more similar to those they like, and less similar to those they do not.
Both of these hypotheses are supported by a number of cognitive-consistency theories. Heider's balance theory for instance suggests that separate, similar entities tend to be perceived as belonging together (“having a unit relationship”). In social terms, a positive unit formation (perceived similarity) should induce a harmonious sentiment relationship (liking).
Perhaps the largest body of research into similarity of attitude and attraction comes from the studies of Ellen Berscheid and Elaine H Walster (Interpersonal Attraction, 1969), and Donn Byrne (The Attraction Paradigm, New York: Academic Press, 1971). Both found that, in general, people are most attracted to others who share similar attitudes. Additionally, people who share attitudes that are considered important, such as home and family, are more likely to be attracted to each other than those who share those considered less important, such as attitudes towards fabric softener.
DONN BYRNE STUDY
In a 1961 study, Donn Byrne investigated the relationship between interpersonal attraction and attitude similarity by recording a variety of attitudes on issues ranging from those considered “extremely important” (such as God, premarital sex, racial integration) to those considered of “minor importance” (such as western movies and television programs).
Afterwards, subjects evaluated a fictional character based on information given on that character’s attitudes. Subjects indicated significantly more positive feelings toward this “stranger” when there were attitude similarities. In general, they considered that character higher in intelligence, morality, and adjustment than characters with dissimilar attitude scales.
In another study, Byrne gave subjects a description of another person and asked how much they thought they would like the person described on the paper. The more closely the other person resembled the subject, the more the subject expected to like the other person.
However, these findings however were criticized for a failure to satisfy external validity, since there was no actual human interaction.
GRIFFITT AND VEITCH STUDY
In response to such criticism, in 1974, Griffitt and Veitch conducted a study in which thirteen unacquainted males lived together for ten days under simulated fall-out shelter conditions. Results indicated a positive correlation between attraction and attitude similarity.
SIMILARITIES TO THE IDEAL SELF
We are not, however, always attracted to qualities that are actually our own, but more often, to those we like to think are our own. In Reik's Theory of Romantic Love, Mathes and Moore (1985) found that people were more attracted to peers approximating to their ideal self, rather than their actual self.
In testing Reik's theory, subjects were given personality descriptions, supposedly belonging to peers of the opposite sex, and asked to state how attracted they were to each. One description was composed of the subject's actual characteristics only; another, his ideal characteristics only; a third, characteristics that were both actual and ideal; and a fourth, characteristics that did not belong to the individual's actual or ideal self. Subjects overwhelmingly were more attracted to peers embodying their ideal characteristics than to those who did not.
Education is also a strong factor in interpersonal attraction. In fact, in 2014, The Economist produced research that claimed that the tendency for those with similar education to be attracted to one another, may in fact be responsible for the growing wage gap between highly and barely educated workers in the USA.
This disparity between rich and poor, they suggested, could have been offset: More women now go to college and enter higher paid jobs for sure, but, had spouses chosen each other at random, many well-paid women would have married ill-paid men and vice versa. Workers would have become more unequal, but households would not. With such “random” matching, the authors estimate that the “Gini co-efficient” (which is zero at total equality and one at total inequality) would have remained roughly unchanged, at 0.33 in 1960 and 0.34 in 2005.
In reality however, the highly educated increasingly married each other so that in 1960, 25% of men with university degrees married women with degrees, as opposed to 48% in 2005.
As a result, the Gini rose from 0.34 in 1960 to 0.43 in 2005.