Thursday, October 23, 2008

Parental Interventions- Environmental vs Genetic

In my "Genetics and Justice" class today we discussed and debated the issue of parents pursuing environmental vs genetic pursuits to influence the development of different phenotypes in their offspring.

My own position on this issue is best captured in my paper "Virtue Ethics and Prenatal Genetic Enhancement". But here I want to float a few further thoughts that came out of the class discussion today.

The reality is that parents have, for better or worse, an enormous impact on the life prospects of their children. They have the primary responsibility for raising, nurturing and loving their children.

Before we turn to the issue of parents being able to directly intervene in their offspring through genetic intervention, let's consider how parents can already modify the biology of their children through environmental intervention.

(1) Nutrition. The food a child consumes (fruits, vegetables, fat, protein, etc.) is profoundly influenced by their parents. The groceries parents purchase determines the "menu of options" available to a child for all the meals at home, lunches packed and taken to school, etc. And nutrition has a profound impact on the physical and mental development of a child. It influences their height, weight, health of their bones and brain development. So what we feed our children influences their biological development. It can set them on the path to health and intelligence, or it can set them on the path towards obesity, disease and intellectual challenges.

(2) Physical Activity. Parents influence the amount of physical exercise their children get. Walking vs driving to school. Playing sports, etc. These all impact the physical, mental and behavioural development of children. These activities can aid muscle development, coordination, self-confidence, team work, patience, etc. Conversely, permitting children to live physically inactive lives can seriously compromise their health and welfare.

(3) Cognitive Development. The neighborhood parents decide to live in influences the educational opportunities open to their children in terms of the quality of their schools. So does the time and effort a parent devotes to reading with their children, helping with their homework, being supportive, etc. The decision to have other siblings also impacts the educational environment a child is exposed to at home (e.g. learning to share with a sibling).

(4) Moral/Social development. Parents can also encourage or discourage friendships for their children which influence many aspects of a child's psychological development. Parent's can help instill a work ethic in their children or they can spoil them. They can raise them to respect certain moral codes or ignore their moral education. Parents can expose their children to religious practices that alter the biochemistry of their brain.

OK, so when we look at the full picture of the range of environmental interventions that parents are free to pursue, we see it is a complex, multifaceted story. But what is evident is that these conventional interventions impact the biological development of children. Indeed, the rise of childhood obesity in the past two decades is clear evidence of how (1) and (2) can pose very significant risks to the health of our offspring. Recognising the risks inherent in environmental interventions is important for it dispels any distorted perception we may be inclined to have that environmental interventions are "risk free". They are not. Many parental actions and inactions, while not falling into the realm of "criminally negligible", still harm their children.

Now when to turn to the prospect of a genetic or pharmaceutical intervention that directly influences the biology of a child parents are likely to rule these interventions out of hand as "unnatural" and "too risky". But I think this is jumping the gun. It all depends on the details. What level of risk is appropriate for direct (vs indirect) interventions? And how effective would these interventions be in enhancing valued characteristics (like health and intelligence)? Children already receive vaccinations that enhance their immune system, even though they have some small risk of harm. So we cannot rule direct enhancing interventions out of hand without more details.

In other words, I think the jury is still out on what may prove to the most effective strategies for parents to pursue to create the conditions for their children to flourish. To date we have subjected our children to the massive social experiment know as "the family", where the biological parents you are born to typically have an enormous amount of discretionary power in terms of pursuing environmental interventions that will influence your identify and biology. And so at this stage we have incomplete data concerning the pros and cons of permitting parents to have this power, and what the pros and cons might be if we had safe and effective genetic interventions.

And finally, we need to critically reflect on what the benchmark for "success" is with respect to parental interventions. What do parents owe the children they have brought into existence? Do they owe them just the minimal requirements dictated by the law (e.g. a life free of abuse and neglect)? Or do we owe them more? And if so, what can best help us provide this for them- environmental or genetic interventions (or both)?

I think we should keep an open mind about this. It's easy for parents to overestimate their ability to give their children "the best". I myself would not rule out any intervention that was demonstrated to be a safe and effective way to develop valued phenotypes in children. The grand social experiment of "the family" has its pros and its cons. And the merits of a genetic intervention should be measured by and against those same standards.