Hetherington's book is probably the best resource. She downplays the negative effects (Look! Only a quarter of kids seem to suffer lasting long-term harm! That's still a minority, just like kids from intact families (~10%) -- ignore the fact that that's two and a half times as many kids...). But, she does report the data honestly. https://www.amazon.com/Better-Worse-Divorce-Reconsidered/dp/0393324133/