We are more likely to choose mates who resemble us in everything from education to body type to physical attractiveness. Researchers in Sweden have now found that people with psychiatric disorders end up with people with the same condition far more often than chance alone would allow.
Partners of people with diagnosed conditions were two to three times more likely to have a diagnosis themselves, compared to the partners of people without diagnoses. Furthermore, when a diagnosed person chose a diagnosed partner, it was likely to be someone with their same condition. This was particularly true in the case of schizophrenia, ADHD, and autism spectrum disorder.
The reason for these pairings isn’t totally clear. But the findings could help explain why disorders like schizophrenia persist, even when they lead to early mortality and decreased reproduction.