New research suggests we tend to marry people with similar religious or non-religious beliefs because we perceive they will have similar personality traits.

Investigators from New Zealand’s University of Otago believe this phenomenon, known as “religious homogamy” is partially a result of inferences about religious people’s personalities.

The researchers measured how religious and non-religious individuals perceive the “openness” of potential religious and non-religious partners. Openness is defined as a primary dimension of personality associated with intellectual curiosity.

They found that non-religious participants in particular associated religious behavior with less openness, and that this inference led them to devalue religious individuals as romantic partners.

In one experiment, religious and non-religious participants decided whether or not they would date forty possible romantic partners who varied in how frequently they attended religious services.

The research team discovered that non-religious participants found potential partners less desirable, and also less open to new experience, as their religious behavior increased.

Investigators also performed a second study in which participants judged potential partners who attended religious services frequently or infrequently, some of whom also disclosed that they were open to new experiences (with statements such as “I don’t pretend my ethical perspective is the only one”).

Non-religious participants again preferred non-religious partners, and also those who were open to new experiences, while religious participants showed the opposite preferences.

Researchers also discovered that the same-religiosity bias was reduced when a partner revealed he or she was open to experience.

As a result of the experiments, it was clear to researchers that religious and non-religious participants evaluate the same open behaviors differently.

That is, there was agreement that non-religious individuals are relatively open-minded, but not on whether being open-minded is a good thing.

Jamin Halberstadt, Ph.D., one of the study’s authors, said the experiments provide insight into one possible personality mechanism behind religious in-group dating bias.

“They illustrate, for the first time, that people’s decision to partner with religious or non-religious individuals can be determined by personality traits that religiosity is believed, rightly or wrongly, to predict, rather than religion itself.”

Source: University of Otago