Parental family variables and likelihood of divorce.

It has long been established that divorced men and women have substantially higher standardized general mortality than same gender persons. Because the incidence of divorce is increasing in many countries, determinants of divorce rates assume great importance as indirect risk factors for several diseases and conditions that adversely affect health. We have undertaken a study in Athens, Greece, to evaluate whether sibship size, birth order, and the gender composition of spousal sibships are related to the probability of divorce. 358 high school students, aged between 15 and 17 years, satisfactorily completed anonymous questionnaires, indicating whether their natural parents have been separated or divorced, their parents' educational achievement, birth order and sibship size by gender. The study was analyzed as a twin case-control investigation, treating those divorced or separated as cases and those who were not divorced or separated as controls. A man who grew up as an only child was almost three times as likely to divorce compared to a man with siblings, and this association was highly significant (p approximately 0.004). There was no such evidence with respect to women. After controlling for sibship size, earlier born men--but not women--appeared to be at higher risk for divorce compared to those later born. There was no evidence that the gender structure of the sibship substantially affects the risk for divorce. Even though divorce is not an organic disease, it indirectly affects health as well as the social well-being. The findings of this study need to be replicated, but, if confirmed, they could contribute to our understanding of the roots of some instances of marital dysfunction.