Nature vs Nurture and Basis of Beliefs: A Response

I wrote this for a discussion in response to an article written by Amil Imani's on Mental Immune System.

Since the discussion got interesting, I could not resist but jumping in and contributing my opinion on the matter.

I would start by saying that Amil Imani's view of the mind initially proposed by John Locke and defended passionately by Margaret Mead [1] and J.B Watson [2] as a blank slate or 'tabula rasa' is inaccurate. From several studies involving identical twins, fraternal twins, real and adopted siblings and measuring their various mental faculties, their response to a particular stimulus etc. cognitive neuroscientists have concluded that nurture alone is not responsible for shaping up a person's personality. The studies involving identical twins have shown a statistically significant correlation between their personalities, however in the case of biological siblings that correlation is much weaker and in case of adopted and biological siblings there is an even weaker correlation in various psychological attributes and personality traits [3].

Therefore, cognitive neuroscientists have determined that approximately half of the personality traits are innate or genetic in nature. Such traits cannot however be considered rigid instruction sets to execute particular tasks, but more like computer programs that are designed to take input from the senses, resulting in certain new thoughts and then translating such thoughts into actions (depending on the inherent brain circuitry (neuron weightings) and how amenable they are to modification by training, reprogramming etc.)[4]

A peculiar case is that of a language, whereas a certain specific language such as English, Spanish or Japanese is not inherent, but the capacity to acquire it is built-in in the human beings. Just like a language is not a fixed vocabulary of sentences but a complex combination of new and old thoughts expressed in it based on some algorithm. Similarly, both biological determinism or absolute behaviorism have been rejected by a significant majority of scientists.

This is the common position among contemporary scientists as specified by Steven Pinker, who himself is a well known cognitive neuroscientist [5] :

"No one today believes that the mind is a blank slate; to refute such a belief is to tip over a straw man. All behavior is the product of an inextricable interaction between heredity and environment during development, so the answer to all nature-nurture questions is “some of each.”

Therefore, even though nature (genes) plays a significant role in shaping the personality of any person, various environmental factors such as early parental rewards and punishment, idols and role models, education, constitution and legislation in the geographical proximity, influence of the peers, cultural, social, religious and economical attitudes all play a role in providing input for the brain programs to respond appropriately.

Religion is important in this sense that it gives human beings the sense of reward for 'good' deeds and punishment for 'sins', creates role models with perfection personified, inculcates the value system and helps creating societal and cultural trends pervaded thoroughly by the religious outlook. Therefore, notwithstanding just the faith of parents, but also how children are brought up and 'guided' to associate themselves to a particular group of peers plays an important role in defining and introducing the in-group and out-group thinking. Studies in the case of adopted siblings have clearly demonstrated that parental influence is over-emphasized and instead they give weight to the values present in their peer-group. However, the peer group also depends on the particular aspect of the personality trait under consideration and members constituting the peer-group may vary depending on the trait considered. In this respect, however, parental influence can indirectly impact the introduction of children to their religious peer-group and have an impact on how they think.

Therefore, behavioral traits that depend on the input provided by the home and the surrounding culture such as language, religion, political affiliation etc. are not genetically inheritable, however, the proficiency of language, the zealotry or the lack thereof in religion and the extent of liberalism and conservative mindset is to some extent inherently acquired. Having reached this point in the discussion, I can say that Amil Imani has overemphasized the existence of malleability of a child's brain, which according to behavioral psychologists can be completely determined by the kind of moulding performed on their minds. However, the importance of early childhood experiences in language, religion, values and surrounding culture cannot be ignored either since they do train a mind to a certain extent (by adjusting neural weightings). Therefore, even though we would always observe a variation on the same issues among different people living in similar socio-econo-religio-political environment, we would observe a large majority influenced to a significant extent by how information has been presented to them, regardless of their inherent psychological makeup.

Even though the example of democrats and republicans experiment, where the candidates chose to vehemently defend their respective political leaders can be a result of genetic makeup as much as the influence of the home and surrounding culture, it did communicate one interesting point. The point was that the rational areas of the brain were not part of the decision making process when a person's mind was biased in the favor of a certain group. In this sense, within the context of this experiment one can say that neither the liberal nor the conservative response could be taken seriously as none of them used their rational faculties (even if they are theoretically capable of using them otherwise). However, this also indicates a presence of a proverbial mental immune system, which similarly makes people re-route the incoming information without taking it through their rational mental channels, due to the inherent biases present in them. It would be instructive in this sense to re-evaluate or evaluate any information consciously on merit instead of employing merely a biased (or prejudiced) mindset to decide in its favor or against it.


[1] Margaret Mead, Sex and Temperament in Three Primitive Societies, 1935
[2] John B. Watson, Behaviorism, 1925
[3] Robert Plomin and Denise Daniels, “Why Are Children in the Same Family So Different from One Another?” Behavioral and Brain Sciences 10 (1987):
[4] Steven Pinker, The Blank Slate, the Noble Savage, and the Ghost in the Machine, The Tanner Lectures on Human Values, 1999
[5] Steven Pinker, Why nature and nurture won't go away, 2004