QUOTABLE:
Judith Rich Harris

"There is... a greater-than-chance likelihood that a person with psychological problems has a biological parent or a biological child with similar problems.

"Heredity is one of the reasons that parents with problems often have children with problems. It is a simple, obvious, undeniable fact; and yet it is the most ignored fact in all of psychology."
Judith Rich Harris, in
The Nurture Assumption,
Free Press, 1998