They say people with opposite traits make for loving couples, but a new study is not obliging with the belief.
The research, published in the journal Evolutionary Psychology, says when it comes to personality, people seek partners with their same qualities - but say they want someone who is different.
To reach the conclusion, researchers quizzed 760 members of an online dating site to answer questionnaires regarding their personality traits, as well as the traits they would want in an ideal long-term partner.
They then were asked if they most wanted a partner that complemented them, or resembled them.
The answers showed a preference for someone with the same sort of personality; the traits, which included neuroticism, extraversion, openness, agreeableness, and conscientiousness, all had positive participant-to-partner correlations, ranging from .51 to .62.
"When asked about their preferences for a mate, people may partially draw upon lay theories of romantic attraction rather than their true desires for a mate," Live Science quoted Pieternel Dijkstra, a professor at the University of Groningen in the Netherlands and the study's lead researcher, as saying.
"Although many individuals occasionally feel attracted to 'opposites,' attractions between opposites often do not develop into serious intimate relationships and, when they do, these relationships often end prematurely," she said.
The study also found that in addition to looking for a similar partner, women wanted men who were conscientious, outgoing, and emotionally stable, all traits that indicate an investment in the relationship and in any potential children.
However, "there were no particular traits that men seemed to prefer more than women," Dijkstra said.