Scientists find biological genes determine the risk of divorce.
The increasing divorce rate is a serious problem and the reasons are investigated by many socialists and psychologists. However, people might ignore a possible biological cause, gene. Data indicates that the adult children of divorced parents are more likely to divorce [1]. This fact indirectly shows the link between genes and divorce but does not remove the environmental factor.
Recently, a group from Virginia Commonwealth University finds the risk of divorce is related to people’s gene rather than their rearing environment after analyzing tens of thousands of Swedish national registries [2]. To study the genetic impact and environmental impact separately, they examine the divorce resemblance among adoptees, their biological and adoptive parents, and their biological and adoptive siblings.
First, they analyze data of divorce between 19,715 adoptees and their biological and adoptive parents. To their surprise, adoptees significantly resemble their biological parents but not their adoptive parents in the history of divorce. Such resemblance provides a direct evidence that genes effect the risk of divorce. This result indicates people are more probable to divorce if their biological parents have divorced.
Then, they test the divorce resemblance between adoptees and their siblings. The data show that divorce resemblance between adoptees and their biological siblings was obviously higher than divorce resemblance between adoptees and their adoptive siblings. This result provides direct evidence that biological genes rather than rearing environment determine the risk of divorce.
Last but not the least, they test the divorce resemblance between 82,698 adoptees and their reorganized family, where one parent provides genes but not a rearing environment, and the other parent provides both genes and environment. They find the divorce rate of offspring is associate with the divorce rate of their not-live-with (NLW) fathers, which also provides a direct evidence of genetic determinant. Meanwhile, they find the resemblance between offspring and their live-with (LW) mothers is stronger than the resemblance between offspring and NLW fathers. This is an indirect evidence that rearing environment also contributes to the risk of divorce.
The direct reasons of divorce are complicated, including drug abuse, criminal behavior, low education, alcohol use disorder, and et. al. The research also finds adoptees resemble their biological parents in these factors. This could imply genes impact bad behaviors of offspring, and thus lead to divorce.
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