Born, made, or both?

The born versus made question is an incredibly complex question to answer. There is scientific evidence that the split is around 40% DNA and 60% development (Jackson & Parry, 2018). However, there is also a "developmental concept of interaction" which "arises from the combination of a particular hereditary constitution with a particular kind of environment” (Tabery, 2014, p. 134, citing Hogben, 1932, p. 98), which is a fascinating idea in itself. When we bring together nature and nurture, we get different outcomes. Sliding doors moments, effectively. Pretty much the entire premise of all science fiction books and films.

Building on that idea, researchers sorted "the Dunedin Study research participants (n = 847) [into groups] based on the serotonin transporter gene variant they carried: s/s (17%), s/l (51%) and l/l (31%). On the environmental side, they divided up the research participants based on the number of stressful life events they had encountered so far in life: none (30%), one event (25%), two events (20%), three events (11%), and four or more events (15%). The combined genetic and environmental difference makers made for a much stronger predictor of depression than either of the difference makers alone" (Tabery, 2014, p. 139). 

I used to think we were entirely 'made'. My personal 'belief' was overturned by the evidence of a family situation (and yes, I know n only equals 1, that I am very much a layperson in this field, and that I am not necessarily an objective observer). But the story goes like this.

My sister had two children (same dad), but the second child was adopted. The adoption was a 'modern' one where all parties were aware and could connect. However, within our family we decided not to overwhelm the 'new' family, and after an all-party discussion, nominated my mother to be the sole contact person. She organised check-ins, presents etc. However, when the siblings were seven/eight they wanted to meet: they had never met before but both were interested in now doing so. They had both had a very different upbringing from each other and had had quite different experiences. They had been educated differently, and had lived in different places. 

I was tasked with organising the meeting, and took them both to the beach in the city where the adopted child was living. These two were like peas in a pod. They had the same mannerisms. They said the same things; they moved the same way, they had the same intonation and pauses in their speech. I was absolutely staggered by how THE SAME they were. Yes, they came from largely the same genetic pool, so it was logical that their voices would be similar, and they would move in a similar fashion because they were structurally alike, but the similarity of two youngsters who were - effectively - two complete strangers meeting each other for the first time shocked me. My beliefs were overturned about nurture being the primary actor, because the evidence of my eyes showed me that nature was playing a far more significant role with these two than I had previously suspected. 

This finding has been replicated in a number of twin studies (Segal, 2021). My sister's children are not twins, but I feel the genetic similarity is definitely a consideration in their case. 

Additionally, someone - and, sorry, I have no recollection who it was - pointed out a number of years ago that when we are born, we can only cry, gurgle, excrete, sleep and drink. EVERYTHING is development from the point of our birth onwards. 

While I know that comment is slightly beside the point, it also illustrates the futility of the argument itself!

Sam

References:

Jackson, B. & Parry, K. (2018). A Very Short, Fairly Interesting and Reasonably Cheap Book about Studying Leadership (3rd ed.). SAGE Publications Ltd.

Segal, N. L. (2021). Deliberately divided: Inside the controversial study of twins and triplets adopted apart. Rowman & Littlefield Publishing.

Tabery, J. (2014). Beyond Versus: The struggle to understand the interaction of nature and nurture. The MIT Press.