Source: The author of a new book says genetics rather than chess lessons have a bigger effect on success, Helen Rumbelow, The Australian, May 16, 2011 (edited)
Researchers have found adult identical twins who were separated at birth to be very similar in almost every way. Here's Bryan Caplan:
"Adoption and twin research provides strong evidence that parenting barely affects a child's prospects."
"If parents gave themselves a big break - or redoubled their efforts - their kids would turn out about the same."
"Tiger parenting is pointless. Kids inherit educational and financial success from their parents. The most influential gift that parents can give their children is not money, connections or help with their homework, but the right stuff."
You can influence a child but it doesn't have a lasting effect.
"By the time your child grows up, the impact of your encouragement and nagging will largely have faded away."
Intelligence is Inborn
The Minnesota Study of Twins Reared Apart reunited 100 separated identical twins. Despite being brought up in strikingly different homes, their intelligence ratings were almost identical.
The Swedish Adoption/Twin Study looked at the intelligence of about 150 pairs of adult twins, about half of them raised apart, and found an even larger effect of genes than the Minnesota study. Upbringing was irrelevant for adult intelligence.
Parents don't influence happiness
The Minnesota twin study found that nurture is equally irrelevant for both joy and sadness.
"By the time you're an adult, your parents' past mistakes are not the reason for your present unhappiness," says Caplan.
Parents barely influence education
A major study of 2,000 Swedish adoptees found that children were [only] 10% more likely to complete college if their adoptive parents had done the same - a similar result to a few other twin studies.
Family has no influence on grades
The National Longitudinal Study of Adolescent Health, on 1,700 children, found that the grades of unrelated children raised together were no more similar than those of strangers.
Parents don't influence income
"The income of the family that an adoptee grew up with had literally no effect on their financial success".
What about the Tiger Mom?
"I find it amazing that she could write that book with next to no mention of genes. Her girls are the daughters of two Yale Law School professors and people are amazed that they succeed at the things they try at?"
"In pushing so hard, Chua is messing up her relationship with her kids. I predict that her daughter will be using the Darth Vader ringtone for her mum on her cell phone."
Isn't her relationship with her kids pre-determined by their genes?
And doesn't skill training influence many things?
What if she teaches her daughter French and the daughter gets a job that requires fluency in French and English? Can that influence her income?
What if she teaches them non-aggressive conflict resolution techniques? Won't that influence their behaviour and happiness the same as any other skill?
How to have great kids
Caplan and his wife rarely make their children do things that they don't enjoy.
"The most effective way to get the kind of kids you want is to pick a spouse who has the traits you want your kids to have.
"The right spouse is like a genie who grants wishes you are powerless to achieve through your own efforts."
Can schools help kids from bad families?
Does this imply that efforts to improve social mobility through the school system are doomed?
"The evidence points that way," says Caplan. "But most social engineering focuses on really disadvantaged kids and twin research doesn't -- because really bad parents are not allowed to adopt.
"The evidence for comfortable families in the First World shows that you can change the family environment a lot without changing the child."
Really bad families are not studied
It is important to note that twin studies do not address neglect or abuse which can damage a child.
They test is whether any of the different styles of OK parenting is better than others.
All the adopting families studied were vetted as decent people but their circumstances varied enormously.
Some were working class, some highly privileged. Some parents hothoused their child with all the best tutors and fancy schools, others let them off the leash.
Yet when researchers tracked down separated identical twins as adults, they found them to be very similar on almost every count.