I'd like to strongly recomend this book, The Nurture Assumption, which has 2 purposes: first, to dissuade you of the notion that a child's personality is shaped or modified by the child's parents; and second, to give you an alternative view of how the child's personality is shaped.
Do parents have any important long-term effects on the development of their child's personality? This book examines the evidence and concludes that the answer is NO.
Nowadays, "heredity and environment" are more often referred to as "nature and nurture". Nature and nurture are the movers and shapers, they made us what we are today and will determine what our children will be tomorrow. No one questions that Good nurturing can make up for many of nature's mistakes, and lack of nurturing can trash nature's best efforts. It seems self-evident.
What I changed my mind about was nurture, not environment.
In human beings, differences in environment account for about half of the variations in personality characteristics. The socialization researchers are correct in believing that environmental factors have effects on children. They are wrong, however, in believing that their research tells them what these factors are. They have failed to consider the effects of heredity. They have failed to allow for the fact that children and their parents resemble each other for genetic reasons. Generalization 1 is true. On the average, pleasant, competent parents tend to have pleasant, competent kids, but that doesn't prove that parents have any influence, other than genetic, on how their children turn out.
Child-rearing is not something a parent does to a child: it is something the parent and the child do together.
Heritability is actually a combination of direct and indirect genetic efects. Behavioral genetic studies are designed to distinguish the effects of the genes from the effects of the environment. The result, for the majority of the psychological characteristics that have been studied, is that roughly half of the variation is attributable to the subjects' genes, the other half to their environment. But the half attributed to heredity includes indirect effects, the environmental consequences of the effects of the genes. That means that the other half of the variation must be due to "pure" environmental influences.
Yes, well-treated children tend to be nicer than those who are treated harshly, but that could be due to child-to-parent effects.
Socialization researchers do not like the idea that some of the effects they report may be due to inherited similarities between children and their biological parents. But the idea that children have effects on their parents, that the relationship is two-way, has gradually won acceptance.
The compilation of stories between identical twins separated early in life and reared in different homes imply that genes can control behavior in intricates ways that cannot be explained in terms of our current understanding of genetic mechanism and brain neurophysiology. The flip side of the coin is that identical twins reared in the same home are not nearly as alike as you would expect them to be. The correlation of personality traits (as estimated by scores on personality tests and in various other ways) is only about .50 for identical twins reared in the same home.
Children who grow up in different families are likely to have very different home environments. The parents' child-rearing style differences between families are claimed to have predictable effects, but, as Maccoby and Martin pointed out, the reported effects are weak and can be accounted for in other ways. The only aspects of parenting that do have effects are those that differ for each child in the family. But if major differencies between homes have no predictable effects, why should we expect the smaller differencies within the home to have predictable effects? Does it make sense to say that what matters is whether Mom loved you best, if it doesn't matter whether Mom was home or at work, married or single, gay or straight?
Nature- the DNA we get from our parents- has been shown to have effects but it can't be the whole story. Nurture -all the other things our parents do to us- has not been shown to have effects despite heroic efforts on its behalf. It's time to look for another alternative, None Of The Above.
