Whether “nature or nurture” is more important in shaping human behaviour has been a subject of debate and discussion for several decades. Ground-breaking research in related areas, especially in epigenetics in the recent years, clearly indicates that the effects of both heredity and environment are intensely intertwined. Let us explore the underlying scientific information that will help us better understand these influences and allow us to examine what interventions are feasible to improve outcomes.
I seek your indulgence to put with some scientific terminology in the first few paragraphs, which I have tried my best to simplify, based on my own limited understanding. In the later part of this blog, effective parenting, which is the main focus of this blog, will be covered in simple less-scientific language.
Virtually every individual on the planet carries a unique set of variations in their DNA sequence, and this is what decides, among other things, your outward appearance or physical traits, your behavioural tendencies, your susceptibility to certain diseases etc. The scientific term for our complete inherited genetic identity is genotype which in common parlance is referred to as “hereditary traits”.
The term phenotype on the other hand takes into account the environmental influences on your hereditary traits that ultimately determine your current personality. Phenotype includes several attributes like your height and eye colour, your overall health and disease history, your behaviour, your propensity to gain weight easily, your tendency to be anxious, your liking for cats and so on. In a sense, phenotype represents all the ways in which you present yourself to the world, part of which is what you have inherited.
Your genome is your complete set of DNA, including all of your genes and in some sense, it is the sum total of your inherited tendencies. The Greek term epi- denotes “on top of” and thus epigenome sits on top of genome and is the complete description of all the chemical modifications to your DNA and histone proteins.
Epigenetics thus is the study of changes in your personality brought about by modification of gene expressions without altering your basic genetic code itself.
Gene expression is such a fundamental well-studied biological process that research on epigenetics has been sprawling in scope and speed. After all, if you have a gene that has been turned off, you are going to look and behave a lot like someone who doesn’t have that gene at all.
We need to first appreciate the enormous influence exerted by the environment on our lives. Here, the term environment encompasses pretty much everything that happens in every stage of your life like social experiences including parenting styles you experienced in your childhood, good and bad experiences you had in your schools etc., nutrition in your food, your hormones, toxicological exposures you undergo prenatally, postnatally and in your adulthood etc. All these do influence your genetic activity through epigenetic mechanisms.
The implication of epigenetic understanding is that doctors and mental health professionals can treat life threatening and dreadful diseases including schizophrenia, post-traumatic stress disorders, mental retardation, autism and neurodegenerative disorders in novel ways.
We may eventually find molecular intervention solutions even for social challenges, such as aging, addiction, suicide, child abuse, and child neglect.
Research is allowing scientists to manipulate epigenetic marks in the laboratory set-up, which means that they are able to develop drugs that treat illness simply by either silencing the bad genes or over expressing the good genes. The great hope of ongoing epigenetic research is that with the flick of a biochemical switch, we may be able to instruct the genes that play a role in many diseases — including cancer, schizophrenia, autism, Alzheimer’s, diabetes and many others — to lie dormant without adversely affecting the individual concerned.
There are other learnings as well. Study of epigenetics shows evidence that lifestyle choices like smoking and overeating can change the epigenetic marks atop your DNA in ways that trigger the genes for obesity to express themselves too strongly and the genes for longevity to express themselves too weakly. The obvious consequence of these differing gene expressions is that you tend to become obese and your life span may be shortened if you regularly smoke or overeat.
While I have discussed so far how epigenetics can help fight dreaded diseases, my blog is meant actually to highlight how with better understanding of epigenetics we can create or influence our living environment for better health outcomes.
Technically, child development can be conceptualized as experiences becoming sculpted in our DNA through methylation, which is one of the major epigenetic mechanisms of change. Incidentally, DNA methylation was first confirmed to occur in human cancer as long ago as 1983 and the pervasive effects of methylation are far better understood now. Without explaining the scientific basis for everything, let me present important findings on the critical need for effective parenting.
It is worth quoting American psychologist and behaviourist John Watson, the 17th most cited psychologist of the 20th century, who said: “Give me a dozen healthy infants, well-formed, and my own specified world to bring them up in and I’ll guarantee to take any one at random and train him to become any type of specialist I might select… regardless of his talents, penchants, tendencies, abilities, vocations and race of his ancestors.”
While this may look like a tall claim, we do have the power to make a huge difference to lives of people with strategic early interventions.
Let us examine how environment and upbringing, especially at an young age can shape or modify naturally inherited tendencies. As an example, think of one strong-willed child in one household who habitually presents a defiant attitude making it very difficult for parents to handle the tantrums. Now think of another strong-willed child in a different family setting expressing this trait very differently by channelling it into an extracurricular activity of his liking. The strong-will makes the child display positive commitment and hard work in order to excel in his chosen field. What therefore becomes important in these kind of situations, is how the personality of the child interacts with his daily experiences. We can hypothesize that the disrespectful behaviour of the strong-willed child could be due to the personality clash with his parents. The difficult situation may be further exasperated by parents not knowing or not equipped to redirect the strong will of their child into more productive pursuits.
While most parenting strategies, literally hundreds of them, are generally effective in theory, the critical difference is the situational context and complexity of relationships that it needs to take into account. You need to appreciate that to make your strategic approaches succeed in managing a defiant child, you may need to make several difficult adjustments in your own lifestyle and may have to tone down your expectations.
Another study looked at so-called ‘warrior genes’ that are generally over represented among violent criminals. Criminal defence attorneys tried to use this as a new defence strategy for violent offenders, claiming that their genes made them do it.
It turns out that the inherited warrior genes by themselves do not engender violent behaviour except in those individuals who grow up in extremely abusive homes. Research indicates that children who are raised by loving parents rarely display any aggressive tendencies even when they grow up.
I cannot emphasize enough that parents exert enormous influence over the healthy development of their children using a variety of strategies like talking and reading to infants, explaining importance of ethical values at various stages, inculcating the need to respect other’s points of view, accepting failures as experiences etc. Many of these important conversations happen around the dinner table. Parents, however, are not the only influencers, especially after children start going to school. There is no doubt that parents have specific responsibility to give their children a good start, but it is equally important for parents to recognize that kids come into the world with their own temperaments.
Parents need to accept the additional responsibility to provide them the right interface and exposure to the outside world that eventually prepares them to become completely independent. The process of child development includes everything from sensory awareness and fine motor skills to language and socialization ability.
Decades of research in developmental psychology, paediatrics and neuroscience converge on the fact that the first five years are especially critical to a child’s outcome. As a child matures, he or she will go through phases where he will explore his environment, learn verbal and reasoning skills, socialize with others, assert his independence from his family, etc.
There is a great deal of research done on the social development of children. John Bowlby, the well-known British Psychologist, the 49th most cited psychologist of the 20th century, proposed one of the earliest theories of social development. Bowlby believed that early relationships with caregivers play a major role in child development and continue to influence social relationships throughout the life.
Bowlby believed that there are four distinguishing characteristics of attachment:
1. Proximity Maintenance – The desire to be near the people we are attached to.
2. Safe Haven – Returning to the attachment figure for comfort and safety in the face of a fear or threat.
3. Secure Base – The attachment figure acts as a base of security from which the child can explore the surrounding environment.
4. Separation Distress – Anxiety that occurs in the absence of the attachment figure.
Bowlby also made three key propositions about attachment theory.
First, he suggested that when children are raised with confidence that their primary caregiver will be available to them whenever they want, they are less likely to experience fear as adults than those who do not receive such attention.
Secondly, he believed that this confidence is forged during a critical period of development viz. during the years of infancy, childhood, and adolescence. The expectations that are formed during this critical period tend to remain relatively unchanged for the rest of the person’s life.
Finally, he suggested that these expectations that are formed are directly tied to their experiences. In other words, children develop expectations that their caregivers will be responsive to their needs because, in their experience, their caregivers have been responsive in the past.
Many of these theories are confirmed by more recent researches. One study published in Development and Psychopathology, claims that the amount of comforting and close contact between human care givers and their babies can influence the amount of beneficial DNA methylation. This adjustment to the children’s DNA may even persist for several years.
In this research conducted at the University of British Columbia and BC Children’s Hospital, the study involved 94 healthy children and their parents. The parents were asked to keep a record of their infant’s behaviour – including fussing, crying, sleeping or feeding – as well as how long their caregiving involved bodily contact. The research was followed up till the babies grew to four and half years when the scientists collected their DNA by swabbing the insides of their cheeks. The results again confirmed that the children who were more distressed as infants and also did not receive as much physical contact, showed a molecular profile in their cells that indicated underdevelopment for their age compared to others.
Although it may sound like someone could be “epigenetically doomed” to bad health if their parents didn’t cuddle them enough, it is gratifying to know that other studies suggest that the epigenetic marks might be reversible with proper interventions.
If research on epigenetics that can control diseases is in its infancy, research on behavioural epigenetics is in embryo stage. Hopefully, not in the distant future, we may be able to discover epigenetic mechanisms that can moderate extreme behaviours, especially like the ones displayed by fundamentalists and extremists. We, however, need to realize the enormous promise of epigenetics will also take an enormous amount of work and lots and lots of time.
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Cuddling Can Leave Positive Epigenetic Traces on Your Baby’s DNA