Perceiving Commitment Levels of Co-habitation

From LiveScience:

Marriage is linked with numerous health benefits that simply cohabiting doesn’t seem to provide. Now, research suggests the reason why — the brain links “just” living together with a lack of commitment and can’t relax.

The new study used functional magnetic resonance imaging (fMRI) to examine the brains of cohabitating and married heterosexual couples, as well as same-sex couples, half of whom considered themselves married despite lacking legal recognition. The findings revealed that parts of the brain are less reactive to stress when somene is with a person they consider themselves married to.

“We really pay close attention to when it’s safe to let down our guard and to outsource our stress response to our social networks,” said study researcher Jim Coan, a psychologist at the University of Virginia.