There has been a lot of research in the measurement of intelligence amongst people of different races and backgrounds. As with any global research, we have conflicting reports, but there is something that everyone agrees on. The two big influences of a child’s success in later life are: biological parents’ intelligence and upbringing factors. First of all, what is intelligence? It could be the IQ score as measured by the famous 77 year old IQ test; it could be the academic grades; it could be mean income when you are 30; it is some combination of these. Many independent researches conclude that a minimum of 40% influence is attributed to intelligence in the heredity. The maximum genetic influence is 80%. Especially the language controls, reading ability and verbal power moves through generations. That is why; siblings reared apart though may have significant difference in success / general IQ always correlate well with each other in their language prowess. In general it is known, that Jews as a race score atleast 12-15 points more than the Asians who score atleast 5 points more than Whites who score atleast 10 more than the Africans. But the reason for these differences though genetic for most part and social and economic in part actually is exhibited differently across groups. i.e., the reason for higher performance of Jews over Asians is not the same as the reason for higher performance of Asians over Whites. Also child-rearing has a big influence on its success when it grows up. The biggest part of this influence is during the developmental years and hence the saying “Woman is behind a man’s success” necessarily refers to the mother rather than the wife :). It is the parents’ attitude towards the child’s performance that shapes the child’s future. When parents set high bars, children typically attain it than when they set low bars. Indians typically set higher standards for achievement (of course there are exceptions) than Americans and that is partly the reason for Indians’ better performance. Hence, a White child when raised in an Indian home that sets high standards for the child will outperform his white peers:). When parents set softer limits and encourage laziness in children (especially true with rich European families) the children perform worse as adults. Lack of breast-fed milk and premature delivery are also reasons that negatively impact performance. Undernourishment and being a witness to negative actions like riots, shooting, and parents’ fighting (including adopted parents) between the ages of 5 and 14 are big factors for low self-confidence and self-assurance as adults. Occupational success of parents, the feel-good factor that they emanate and the socio-economic status of a growing child play a key role. Inferiority complex developed as a child does not go away until he is able to prove to the world that he is also capable. They grow up to either being spend-thrifts in general or spend-thrifts in friends’ presence. The constant worry about what others might think gives them in to peer-pressure and negatively impacts performance.

Moral of the story: You thought I was going to say – blame your parents!
Nope!
If you think the upcoming generation will definitely marry a person of lower IQ caste, you are encouraged to adopt such children and benefit them so that as a race, they get better :)
p.s. If I sound like a racial person, I am not one!