autz you seem to have a pretty generous notion of what an ideal family life consists in. You also seem to assume that physical abuse is the only kind of treatment that can result in serious emotional disturbance. From your own link on Bundy we have a few details that seem not to have registered your radar. For example,
“Shortly after Ted’s birth he and his mother moved back to Philadelphia to live with [his mother’s] parents who he would later refer to as his mother and father. This charade allowed Eleanor to escape any harsh criticism and prejudice for being an unwed mother. Theodore grew up referring to his own mother as his older sister.”
and
“[His mother] and [her new husband] were to have four other siblings who Ted spent much of his time baby-sitting after school. Ted never really took to his new father who tried unsuccessfully to raise him as his own son, by including him in camping trips and other father-son activities. Ted had his own ideas and thought of himself more as a Cowell…”
“As a youth, Ted was terribly shy and was often teased and made the butt of pranks by bullies in his junior high school. Regardless of
the sometimes humiliating experiences he suffered [he had good grades]”
Now I’m not suggesting that what we have here is a a surefire pattern for “nurturing” a serial killer. But what we do have is an intelligent kid who seems to have had to contend with his and mother’s shame, with being or feeling alien towards his stepfather, with being separated from peers by onerous childcare duties and by teasing/bullying. (It also sounds, from this brief snippet, like the mother may have been depressed through much of her life, but that could be me reading into some unexplained details.) In any case, lots of isolation and disconnect from the family; humiliation at school. I’m not a psychologist by any means but that sounds like the kind of stuff you often read about in the profile particular to serial killers.
As I see it, it would be pretty difficult to overstate the importance of nurture in emotional and–just as important–intellectual development.
I don’t doubt for a second that certain aspects of our personalities our give to us by nature; but what we do with them is entirely the product of nurture. Consider that everything that we learn, everything experience we have, all of our friendships, all that we read, and see, and do from the time we are born on–is “nurture.”
Are you really ready to discount all of that just because you could recognize differences in temperament in your infant children? (If you think back, btw, I doubt you recognized those differences as soon as one week after birth, unless you attribute a great deal to how much a baby eats, sleeps, and cries 
).
To put the question a different way, what kind of people do you think your children might have grown up to be had they been raised as 9th century Vikings? or the adopted children of a Hollywood celebrity? or factory children with no schooling? Do you feel certain that they would be exactly the people you know them to be even if the environment that you helped to create for them had not existed and some other took its place?
