A new study of adopted children finds that the propensity to divorce may be partly genetic rather than a learned behavior. The study found: “Children were 20% more likely to divorce if their biological parents had divorced than if those parents had stayed together, but no more (and no less) likely to do so if their adoptive parents had split up.”
https://www.economist.com/news/science-and-technology/21736124-according-study-adopted-children-genes-play-role-likelihood