In training and lectures I discuss the idea of homophily. This describes the how we tend to be drawn to others who are similar to us in personality, values and social status (for a review click here). For example, this describes how young people come together in like-minded groups who then amplify and normalize their behaviors (click here). Or how echo chambers are created in social and virtual worlds where the like minded flock to similar networks and reiterate the same ideas and exclude others (click here).
It also relates to how partners come together who share similar temperaments.
A significant proportion of personality is inherited from parents. Mate selection based on homophily can amplify personality structures. Fretful individuals tend to have children with fretful partners, meaning that their offspring are more likely to be fretful too. Impulsive individuals tend to partner with impulsive partners increasing the likelihood of impulsive children. Even psychopaths are happier in relationships with other psychopaths (click here).
This recent article in the Conversation caught my eye, which is one of the largest studies of partner selection in romantic relationships. What is particularly interesting is that it included the ex's and the current partners of participants. So the study tracked peoples history of partners, not just the current partner. To read the results, click here.