Sociologists from Ohio State University have found that children from large families have markedly lower divorce rates.
The equation that emerged after a 40-year study, involving a sample of 57,000 American adults, was simple: The more siblings you had as a child, the less likely you were to be divorced as an adult. The researchers don’t offer an explanation for this phenomenon—in fact they seem to be stumped—but they know it’s not because the children from large families don’t marry. On the contrary, they’re more likely to marry, and more likely to stay married, than their small-family counterparts.
We already know that among married couples who don’t use contraceptives, the rate of divorce approaches zero. Obviously these couples are more likely to have multiple children. So by eschewing contraceptives, a married couple is taking a huge step to guard against divorce—not only for themselves, but for their children as well. http://www.catholicculture.org/commentary/the-city-gates.cfm?id=634