Nature vs. Nurture: A look at neurobiology

Nature NurtureNature-Nurture: The basics

The Nature-Nurture debate has been long-standing in academic, social and online settings. People vehemently engage in arguments over whether or not we are shaped solely by our biological underpinnings or the environment we interact with. This is often an “either-or”, rather than a “both-and” dispute.

Things can become quite heated as one party urges that we’re simply byproducts of our genetic and physiological make-up (where our thoughts, emotions and behaviours are governed by how we are put together biologically) and the other states that we are no more than the outcome of our early and ongoing experiences and interactions with the outside world.

When we really think about it, this should not be a question of whether bread is comprised of either water or flour, but rather that they are both necessary and important. What should be considered, and of the utmost importance, is how they are put together as well as the nature of these ingredients.

That is, we should consider the history of the ingredients: where they came from, how they were manufactured, their delivery to you, as well as how they are put together, in this instance, to create different kinds of bread.

Essentially, when we acknowledge that we are influenced both by our biology as well as our environment; we can start asking more pertinent questions about how these two factors interact to create the very unique selves that we are.

Such as: What aspects of our ancestral history inform our biological make-up? Does having a genetic predisposition determine who we are, or does the impact of the environment contribute to whether these genes are expressed or not? Can engagement with the environment inform our biological make-up and thus influence who we are?

A look at the brain

The last question is one that is frequently asked within the fields of neuroscience, molecular genetics, psychiatry and psychology. Historically, scientists used to believe that when we were born, we came into the world with a set number of hard-wired neurons and connections within our brains. They believed that, over time, our brains would slowly lose neurons and nueuroconnections – leading to ultimate brain degeneration.

However, modern studies yield that, in fact, the brain is highly elastic and malleable (called neuroplasticity) – creating new connections and pathways all the time. Furthermore, they note that the highest rate of neuroplasticity is between the ages of 0 to 5 years of age. This is when the brain is most vulnerable and susceptible to being influenced by the outside world. After the age of 5 years, the brain continues to create neural pathways, but to a lesser extent.

These pathways are reinforced through increased exposure. Herein, If an event is repeated over and over again, then the likelihood of it shaping neural pathways in the brain is larger (compared to a once-off experience). That being said, exposure to a highly influential once-off experience can also play an important role in determining the internal workings of the brain.

The not-so-ideal

Scientists have studied different types of parenting and noted the impact this has made on the biological stress-reactions of an infant. They noticed that infants, who were neglected or treated adversely, endured higher levels of a stress-hormone that ultimately made them more susceptible to later psychopathology. They also had a decrease in ability to process and manage stressful events later in life

If we experience danger (such as physical abuse), stress hormones are released that lead to a fight-or-flight response. This response acts as a way to protect us from harm. Repeated exposure to adverse environments leads to strengthened neural responses that are self-preserving. In this instance, we could be hyper vigilant, tense and on-edge as we anticipate the prospect of danger and await to respond to that danger. In this instance, this response would inherently shape one’s neurological make-up to such an extent that it becomes more and more common.

Consider what it is like taking a walk in a grassy veldt for the first time. It’s difficult to create a path. A person really needs to push through the grass in order to move forward. However, the more often this path is walked, the more engrained and evident it becomes, leading to it being travelled more frequently. A similar concept may be considered when thinking about the brain and neural pathways forming. The more often this pathway is travelled, the more likely it is to be travelled again.

When things go well

Studies conducted on rats during infancy yield extraordinary results. Scientists have discovered that mothers who were sensitive, responsive, affirming and attentive, provided their infants with an environment where stressful events could be tolerated with greater efficacy.

They provided their infants a “buffer” from the outside world – making it feel safer and more secure. Later in life, these rats grew up being able to tolerate and manage adverse experiences. In a sense, these early-most experiences during infancy gave them the impression that the world is tolerable. It made them able to endure ambivalence or hardship by having a sense that they can feel safe and secure. Similar outcomes have been shown in human infants.

Nature and Nurture: A marriage of two very complicated notions

These studies illuminate what psychologists have been theorising for decades – that our most early experiences shape who we are and who we ultimately become. They inform our thoughts, behaviours and emotions and do so in a very real way – through the body. The extent to which our experiences create an impact on us is a very complex and convoluted process.

It depends on an array of factors, which can include (but are not limited to): history of ancestral predecessors, genetic formation, prenatal exposure, birth experience, early childhood experiences (most importantly the consistency thereof) and later experiences in life. All of these factors come together to create you…an ultimately unique individual with a story.

Leave a reply


Copyright © 2019 Milica Repensek. WebSite designed by Web and Video Marketing