USA: „Children who grow up without their biological father perform worse on standardized tests, earn lower grades, and stay in school for fewer years, regardless of race and class. They are also more likely to demonstrate behavioral problems such as shyness, aggression, and psychological problems such as increased anxiety and depression. […] Generalizations are dangerous; many single parents are doing a terrific job under difficult circumstances. But on average, children from single parent families do worse in school and in life.“
Univ.-Prof. Dr. Robert Putnam, „Our Kids: The American Dream in Crisis“ (2015), S. 78f