Nature versus nurture? The ongoing search for understanding.

08 - May - 2022

This is a question which is probably as old as humanity itself but first credited to psychologist Sir Francis Galton in 1869. Ever since, many studies have been conducted, trying to discover the reasons behind the most common mental health problems. The appliance of scientific study to human behaviours generally serves only to raise more possibilities and lines of enquiry. And whilst much greater understanding exists around the physiology that accompanies psychological distress it is not that there is categorical certainty about whether and which might come first.

As psychotherapists our role is to facilitate someone getting to the most helpful understanding of their concerns so that they can make skilful decisions about how to live life. Therapy exists at the point current medical knowledge ends with a view to helping someone live better with “what is”. Sometimes that might mean learning to live with a medical diagnosis and at other times a difficulty for which there is currently no known medical understanding.

Many people and scientists question whether our mental health is affected by nature, meaning the genetics and hormonal factors which impact certain behaviours, or nurture, which are the environmental and cultural factors, as well as experiences during the childhood and teenage years. In the context of nature vs. nurture, “nature” refers to biological and genetic predispositions which impact human traits, and ‘’nurture’’ focuses on the influence of learning and other influences from the person’s environment.

The studies have shown that nature, or genetics and disposition factors are present with some mental health conditions, such as bipolar disorder or major depression. According to these studies, bipolar disorder is four to six times more likely to exist when there is a family history of the condition. However, other studies also discover countless cases of people who present with mental health disorders, yet they do not have a clear link to mental health disorders in their family tree. This has led to more scientists and psychologists exploring the ‘’nurture’’ influence of mental health illnesses.

Although the significance of genetic predispositions has enabled the question of causality from nature to remain unanswered for mental health issues such as Bipolar Disorder, research on other mental health illnesses have highlighted more contextual rather than biological factors. For example, according to studies on identical twins who share the same genes, if one twin develops schizophrenia, research shows the other twin only has a 50% chance of also developing the condition. Schizophrenia is known to run in some families, indicating the possibility of a genetic component to the disease, however 90% of cases of schizophrenia are classed as non-genetic.

Studies conducted at the University of Liverpool claim that while a family history of mental health conditions is the second strongest factor of mental illness, the strongest factor is in fact life events and experiences, such as childhood trauma, abuse or bullying. This supports the theory that nurture plays a significant role in the development of mental health related issues.

There are many other statistics which support this theory. When we look at the nurture factors, the statistics claim that mental disorders are 38% more common in urbanised and industrial neighbourhoods when compared to rural towns and villages. Mood disorders such as depression were found to be 39% more common in urban cities, anxiety disorders increased by 21% and schizophrenia rates doubled. Although it’s unclear whether or not this increase is directly due to stressful city living, the findings indicate that people who live in rural areas are less anxious and stressed and that living in recreational areas positively affects mental well-being.

Multiple studies also suggest that having a window view from an apartment or work office which overlooks a natural setting can enhance memory, attention, impulse control and mental health well-being. Research reports from Stanford University suggest that a lack of interaction with nature could cause a decrease in psychological health for those who live in the city. The same research also suggests that interactive activities, such as going for a walk in the nature setting or being with friends, can stop the depressive thoughts and long-term depressive episodes. In one of the studies, Stanford researchers asked some participants to engage in a 90-minute walk through the city, while others were asked to take a 90-minute walk through a nature path. They measured the participants’ blood flow and those who participated in the 90-minute nature walk had lower levels of rumination and sgPFC activity compared to those that walked through the city. The research concluded that natural environments bring positive effects on mental health through enjoyable sights and sounds.

Although nurture factors in the cause of mental health illnesses have been explored more in recent years, nature factors and genetic predispositions also cannot be ignored.

A British team has found that pregnant women who have a major emotional loss in the early months of pregnancy give birth to babies with a higher risk of schizophrenia. Abel’s schizophrenia study looked at 1.38 million babies born between 1973 and 1995 and confirmed the similar connotation. The study found the risk of schizophrenia was 66% higher among offspring whose mothers experienced the death of a relative during the first trimester. The link disappeared after the first trimester, however, after the first months, barriers between mother and foetus are formed, that protect the unborn baby from stress hormones released by the mother. Abel said it was possible the mother’s hormones may either have a direct impact on development of the foetus brain or affect it indirectly by altering the activity of certain genes.

The studies, published in the Archives of General Psychiatry, add to the growing possibilities of how both genetics and environmental distress sometimes act together to produce mental illness. “It is not a question of genes versus environment. It is a question of how genes interact with whatever the environmental factors might be. And that is probably true of all of the disorders that we call mental illness,” said Dr. Thomas Insel, Director of the National Institutes of Mental Health.

Ultimately whether mental health is the outcome of nature or nature or the complex interweaving of the two, probably the most important take out is that when there is a struggle there will rarely be any quick fixes. A struggle is a call to action and it is an act of kindness and compassion to give time and energy to ensuring greatest understanding and awareness – as this is the basis of skilful living.