This is depressing. When unmarried men become dads, research out of Michigan shows they are more likely to acknowledge paternity if their newborn is a boy. From D’Vera Cohn at the Pew Research Center:
As the number of babies born to unmarried mothers has risen, so has interest from government officials in persuading unmarried fathers to sign a paternity acknowledgement form that gets their name added to the birth certificate. It’s standard practice now for hospitals to ask those dads to sign–but not everyone does. What makes a difference in who signs?
The child’s sex, for one thing, according to a recent analysis of more than 1.8 million birth certificates in Michigan. The analysis, published in the online journal PLoS One, finds that unmarried men who father sons are more likely to acknowledge paternity than fathers of daughters. The effect was slight—a male baby is 4% more likely to have a father who acknowledges paternity, relative to a female baby—but statistically significant.
Read more here.