A large-scale study of over 6 million couples across Taiwan, Denmark, and Sweden found that partners are more likely to share similar psychiatric diagnoses, possibly due to assortative mating, shared environments, attachment styles, and social identity factors, though the study is observational and does not establish causality.
Research suggests that damaged people tend to bond with other damaged people due to shared experiences, corresponding perspectives, and mutual acceptance. Female friendships, in particular, can help alleviate stress and promote healing. These friendships provide grounding, understanding, and a non-judgmental space. Having a friend who has been through similar experiences creates a strong bond and fosters empathy. Friendship becomes a priority in navigating the challenges of life and offers support in recovering and healing from past mistakes.