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July 20, 2016

Are our children a product of the genes we pass on to them, or the way in which we raise them? Psychologist Dr Ruth Jillings looks at the current thinking and research. 

Are Kate Hudson and Goldie Hawn actresses because nature smiled upon them and gave them the gift of artistic genes, good looks and the confidence to perform in front of others? Or is Kate Hudson an actress because she grew up with Goldie Hawn, who was not only a role model for her daughter but also provided her with an inspiring environment complete with actors for friends and multiple opportunities to get into acting?

Is Lydia Ko a great golfer because she comes from a family with excellent sporting genes and a stable temperament, or because her father trained with her eight hours a day from her earliest years and helped her develop that ‘cool as a cucumber’ demeanour? 

Is your child kind because you are a great parent who has taught and modelled prosocial behaviour, or was kindness filtered down through your genes?

Why am I useless at all musical instruments and unable to sing a note when my grandmother was a highly regarded pianist and my mother-in-law sang with Kiri Te Kanawa? Did I squander my children’s potential musical talent because as a family all our free time and energy has been devoted to sport? Did I provide the right genes, but the wrong environment?

This is the essence of the nature versus nurture issue.  The question is whether each of us is hardwired to develop the way we do because of our DNA, or whether it is our life experiences and environment that determine the way we turn out. In a nutshell, nature refers to all the inherited genetic stuff. Some scientists think that our personalities are based on genetic predispositions, aka nature. Other scientists favour the nurture approach and think the way we are is due to our life experience, the bits and pieces we are taught, and the environment, family and culture in which we grow up. They emphasise the importance of all the environments to which we are exposed (including in utero) and all the experiences we have after we’re born.   

This debate includes some big questions. Is there a gay gene? Is violence shaped by our environment or are tendencies towards violence wired in before we are even born? Researchers spend years of their lives exploring these issues, but parents are also hugely invested in knowing if their little darling emerges fully formed or as a blank slate for their parenting input.

Genetic traits can be easy to spot. The first thing parents look for when they gaze in wonder at their newborn is who they look like. It is a great comfort to see that your little miracle has your eyes and your partner’s olive skin. Families often have quirky little genetic markers that distinguish them in some way.  For some, this genetic legacy can take the devastating form of inherited diseases. In our family, despite our desire for curvy figures, all the girls have small boobs and funny-shaped little toes!  

Inherited characteristics are usually pretty obvious.  Some influences from the environment are also obvious, including accent and preferences for certain foods, but things quickly get more complicated when we wonder where we got our love of reading, or sports skills, or tendency towards anxiety. This is the trickier stuff that is much harder to answer and fuels the nature versus nurture debate.

Over the years scientists and society have swung in terms of whether nature or nurture has more support.  For example, in the 1960s there was a trend towards behaviourism. At the time popular thought was that our personalities were mainly determined by our environments and experiences. I can remember a time not long ago when anorexia and schizophrenia were thought to be influenced by ‘cold’ mothers!

The most tragic example of this thinking was when John Money, a Kiwi who was world-renowned in terms of gender issues, attempted the ultimate in nurture experimentation when he tried to demonstrate that gender is simply a matter of early conditioning. In what became known as the ‘John/Joan case’, he persuaded the parents of a young boy who had lost his penis during a disastrous circumcision, to raise him as a girl.  Money was convinced gender didn’t matter and at 22 months the young boy had gender reassignment surgery. At first things appeared to go well but the experiment failed when John/Joan committed suicide after suffering years of depression. Tragically, his twin brother suffered from schizophrenia and also died after an overdose of his medication.

A huge study published this year in the journal Nature Genetics authored by Polderman and colleagues looked at 14.5 million(!) pairs of twins to try and determine the underlying causes of personality, intelligence, health, and likelihood of mental illness.  The researchers looked at almost every twin study conducted in the last 50 years. Twin studies are incredibly useful because identical twins share almost 100 per cent of their genes and the same environment (except for those raised apart, which delights scientists because it gives them even more information to work with). Fraternal twins share around 50 per cent of their genes and the same environment, so with all this information it’s possible to estimate the contributions of genes and environment.  

The results of this massive study put the impact of genes and environment at around 50/50. In terms of personality, intelligence and health it seems nature and nurture are approximately equal contributors, although there were a few exceptions. For example, bipolar disorder and schizophrenia were found to be 70 per cent genetic and only 30 per cent due to environmental factors.  

Social values like kindness were found to be 70 per cent influenced by the environment and only 30 per cent by genetics. This is great news for parents because it means what we pass onto our kids via our words and actions really makes a difference.  

A fascinating example of this is the potential gene for psychopathy. If this sparks your interest, take a look at James Fallon’s TED talk ‘Exploring the Mind of a Killer’. James Fallon is a respected academic and neuroscientist who, in the course of his research, was stunned to discover that he had the brain of a psychopath and even more stunned when his mother told him about the multiple murderers in his family tree, including the notorious Lizzie Borden. 

He believes that despite his genetic legacy he was saved from the dark side by growing up in a nurturing and loving environment that allowed him to become a successful adult and prevented him from developing the traits of psychopathy.

Some questions are still unanswered. A hugely active area of research is looking at finding the ‘gay gene’.  This gene would mean that homosexuality is no more of a choice than eye colour. Researchers feel that they are very close to this discovery.

It is not easy to be a parent now. There is so much pressure to do it ‘right’. Previous generations were concerned that their children’s manners and behaviour reflected well on the family, while our generation feels pressured to maximise a child’s full potential. Previous generations saw a child with a particular talent as a gift from God, while these days we grab any hint of talent and work it hard with dreams of creating future All Blacks or Tall Ferns.  

Even if the theories are outdated, parenting remains in the grip of the ideas of Sigmund Freud, who promoted the view that parents are completely responsible for the way their children turn out – at least psychologically. Other psychologists, including Erikson, introduced the theory that children go through various stages and that there are potentially good and bad outcomes associated with each stage.  As you may have guessed, parents are held responsible for all outcomes - good and bad. 

So what does all this research mean to the average parent? After all the studies it seems nature and nurture don’t separate easily; rather they interact and work together.  It looks like nature determines the range of our potential, while nurture affects the ways in which our potential is actualized, in the sense that it can be helped or hindered by the environment. The truth is that when it comes to people, there is still so much we just don’t know.  

For me as a psychologist, but always primarily as a mother, my take-away from all the complexity and confusion of the nature versus nurture debate is quite simple: firstly, I need to accept my children as they are and for what they are, with all their interesting quirks and especially in terms of the ways they differ from me. I want to accept and appreciate the unique parts of them that probably came from the nature side. Secondly, I see my job as doing whatever I can to give them the best environment. I want to provide a warm, stable, loving home and opportunities for them to be the best they can be, but in a supportive way, without pressuring them. Given that I am not perfect, I just try to manage the mayhem, do my best every day and let myself off the hook on the days when I do an average job.  

The nature/nurture debate might be complex but maybe it’s time we made parenting simpler, took some of the pressure off ourselves and trusted that we are doing a good job.


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