Nature versus nurture- the fundamental question that has plagued (for lack of a better word) psychologists, neuroscientists, biologists, anthropologists, philosophers- and probably, anyone trying to gain any sort of a comprehensive view point of the world.

Despite being juxtaposed frequently, I would argue that it is impossible to disassociate nature from nurture when discussing development. While many characteristics- both physical and behavioral- are determined by genotype and phenotype, the environment influences the two. Dobzhansky (1955) conceived the concept of a “norm of reaction:” depending on the environment, any genotype could yield any phenotype, (Siegler & DeLoache, 2006). Behavioral characteristics are multifactorial yielding various phenotypes.

And of course, there is the emerging epigenetic research. People all over the world are now studying how environmental factors “can alter the functioning of genes and create stable change in [the expression of certain epigenetic mechanisms,]” (Siegler & DeLoache, 2006) that can be passed down to the next generation. These changes are a result of methylation which silences gene expression and are linked to explaining differences between people growing up in wealthy versus impoverished environments.

The simple response is to say that people growing up in wealthy environments just have greater resources. Some note the differences in SAT scores between students of wealthier backgrounds and those in working class families: private schools, tutors, jobs after school. Others focus on the direct differentiation between early education and the types of teachers students have at an early age. I think that family environment plays a huge role.

A while back, the New York Times reported on a case they termed “The Mixed Up Brothers of Bogotá.” The case brought up some interesting points since the environments that the two pairs grew up in made for an epigenetic study. Within the study two pairs of monozygotic (identical) twins were switched within a hospital and raised separately as two pairs of fraternal twins. One fraternal pair was raised in the countryside away from the capital city of Bogota in rather poor conditions, while the other pair grew up within the city.

Identical twins being raised apart. What could be a better way of testing the nature vs nurture hypothesis?

If a pair of identical twins that share all of their genes are more similar to each other in terms of a specific trait than the fraternal twin with which they grew up, this would suggest that genetics contribute more to a given trait’s expression. The latter speaks to the “Jim Twin” study which was dug up again with the Bogota case, in which two pairs of twins that were separated at birth had wives and children with the same names, the same preferences for brands and the same favorite vacation spot, (Dewey, 2007).

However, within the Bogota case, Segal (the researcher that worked with the twins) found that the Colombian monozygotic pairing was less similar behaviorally than she had expected, despite certain characteristics that were cited. This would suggest that their environment took more of a toll.

http://www.nytimes.com/2015/07/12/magazine/the-mixed-up-brothers-of-bogota.html