Psychologists Matthew Montoya and Robert Horton came to a similar conclusion in their own analysis published in the Journal of Social and Personal Relationships. Instead of conducting a single new study, they reviewed and analyzed dozens of past studies that investigated whether similarity leads to attraction. What they discovered is strong evidence that two people who resemble one another in terms of personality, attitudes, interests, and other traits are likely to find each other appealing.

People, then, who see each other as wildly different — opposites — will likely find one another undesirable. So magnets yes, humans no. What, then, explains this human behavior?

The work of psychologist Donn Byrne suggests one possible reason. His research, also appearing in the Journal of Social and Personal Relationships, showed that people feel more comfortable with those who are similar (as opposed to dissimilar) to themselves. A separate study, published in Communication Monographs, suggests that exchanges, communication, and contact between individuals with a lot in common are smoother and so more enjoyable and gratifying than between divergent pairs.