The “Twin Bond” Study: Why Identical Twins Are Choosing Each Other Over Their Spouses

Romantic relationships are often expected to become a person’s primary emotional bond during times of stress, major decisions, and separation, however, a 2015 study found that this pattern does not apply to everyone.

Its findings suggested that many identical twins continue to place their co-twin above their romantic partner in their attachment hierarchy.

The research, however, did not conclude that these twins cared any less about their husbands or wives. 

Instead, the findings suggest that growing up alongside an identical sibling can create a uniquely strong sense of familiarity and security that remains important well into adulthood.