This summary of a Brookings Institute study on marital and family trends from 1970 to 2010 implies U.S. kids are increasingly at risk of ineffective parenting:  http://sfhelp.org/parent/news/trends.htm

I've studied human development and family-system functioning professionally for 33 years. I conclude that a largely-unhrecognized source of personal and social "problems" is an inherited [wounds + unawareness] cycle : 1) young kids are parented ineffectively, and develop up to six specific psychological " wounds " to survive. 2) without parental recovery and family-system imporovement, kids leave home and choose similarly-wounded, unaware mates - repeatedly. Many of them...