Obviously our genetic make up is ultimately responsible for everything that we are, biologically speaking. There's no escaping that. But for purposes of this debate, if we are to isolate those factors that are most responsible for producing analytical thinkers, once we assume that we're all (mankind) composed of roughly the exact same stuff going on at a genetic level (10 fingers, 10 toes, two eyes, etc.), the difference between analytical thinkers and non-analytical thinkers becomes one of upbringing and environment.
Now you bring up an interesting twist to environment - and that is the fact that environment is largely shaped by culture & race. Whites tend to live around other whites, blacks around other blacks, professionals around other professionals, blue collar workers around other blue collar workers, etc.
Environment is an interesting dynamic made up of many different factors. What's even more interesting is when we take a an astute young white male like Winthorp, take away his job and put him in the ghetto and simultaneously take a downtrodden young black male like Valentine, pull him out of the ghetto and give him an ivy league job. The proof is all around us everyday - people from well off families tend to do well academically. This makes sense when you consider that once you can eliminate negative environmental factors, such as where your next meal is coming from or where you will sleep tomorrow, etc. you can begin to allow your brain to analyze items more academic in nature such as mathematical formulae, logic problems, and the like.
- Randolf
Randolf, you're referencing movies. Even if the stories in these movies are true (and I have no doubts that they could be true), they are only anecdotal and only illustrate your point--not prove it.
What does science have to say on this issue? I can't find any recent literature that places non-genetic factors before genetic factors on intelligence.
Longitudinal genetic study of verbal and nonverbal IQ from early childhood to young adulthood.
Hoekstra; Bartels; Boomsma
Learning and Individual Differences. 2007 Vol 17(2) 97-114
In a longitudinal genetic study we explored which factors underlie stability in verbal and nonverbal abilities, and the extent to which the association between these abilities becomes stronger as children grow older.... Genetic influences seemed to be the driving force behind stability. Stability in nonverbal ability was entirely explained by genes. Continuity in verbal abilities was explained by genetic and shared environmental effects. The overlap between verbal and nonverbal abilities was fully accounted for by genes influencing both abilities. The genetic correlation between verbal and nonverbal IQ increased from .62 in early childhood to .73 in young adulthood.
Genetic and Environmental Contributions to General Cognitive Ability Through the First 16 Years of Life.
Petrill; Lipton; Hewitt; Plomin; Cherny; Corley; DeFries
Developmental Psychology. 2004 Sep Vol 40(5) 805-812
The genetic and environmental contributions to the development of general cognitive ability throughout the first 16 years of life were examined using sibling data from the Colorado Adoption Project. Correlations were analyzed along with structural equation models to characterize the genetic and environmental influences on longitudinal stability and instability. Intraclass correlations reflected both considerable genetic influence at each age and modest shared environmental influence within and across ages. Modeling results suggested that genetic factors mediated phenotypic stability throughout this entire period, whereas most age-to-age instability appeared to be due to nonshared environmental influences.
And there are many other articles like these.