This is the classic nature vs. nurture debate.  It is a topic that fascinates me and one in which I have now reached my third major, and I hope, final position.  I was spurred to write this because of something Glen said over at PluginID with his latest post: Personality Development: Be Who You Want to Be.

He said:

“I don’t think I like the idea that our personality and specifically our behaviors are largely proven to be based around our genetic make-up.”

Way back in the 70’s I was nurture all the way.  I believed we were born tabula rasa (blank slate) and that we were built by our environment and our choices.  Back in those days nurture ruled the debate.  There really wasn’t much of a debate at all.  That’s what everyone thought.

By the end of the 90’s, nature had slam dunked nurture into the waste bin of history.  The evidence was overwhelming.  Even though I didn’t like it, I was resigned to the fact that we were largely a product of our genes and the interaction between those genes and the environment.  I’m very scientific and the evidence was powerfully convincing.  I chose to believe the evidence and not my wishes that it not be so.

Now as we draw to the end of the 00’s (boy that sounds weird to say), I have a new position.  It is not simply 50/50 nature/nurture.  I have decided, and I didn’t read this anywhere – it just slowly dawned on me, that there are two questions.  The answer to the first is nature, and the answer to the second is neither nature nor nurture.

Question 1: Are humans as a population largely the product of their genes?

In many ways, I am sad to report, the answer to this question is yes.  I’m not going to argue the point here, but there are many resources on the Internet as well as a wealth of books that argue that fact persuasively.  This is one case where statistics do indeed prove the fact.  One of my favorites is now a classic of sorts even thought it was published only seven years ago: The Blank Slate: The Modern Denial of Human Nature

Studies show that identical twins adopted at birth, raised apart, and never knowing each other are extremely similar.  Biological siblings adopted at birth, raised apart, and never knowing each other are about as similar as biological siblings raised together in the same family, but they are less similar than identical twins.  Unrelated siblings adopted at birth and raised in the same family are not much more similar than people randomly chosen from the street.  Children adopted at birth and raised apart from their biological parents are about as similar to those parents as are children raised by their biological parents.

This was all shocking to me and difficult to accept when I first read about it.  It seemed to slam the door shut to much of our free-will.

This is just one small area and it goes on and on.  The evidence converges from many different directions and is almost irrefutable, at least with our present knowledge.  But this is all missing my main point, which is the answer to question 2.

Question 2: Are individuals a slave to their particular genes?

Here I believe we get an entirely different answer.  My answer is an emphatic NO.  You can’t prove this statistically and it is a much more subtle argument, but it is a position that has allowed me to reconcile my personal experience and observation to the powerful scientific evidence referred to in question 1.

You may think this answer contradicts the first answer, but it does not so let me explain.  It may be indeed true that with large populations genes rule.  But that is a statistical fact about the whole and does not take into account individual variations.

For example, you may study 1,000 pairs of identical twins adopted at birth and raised apart.  You may come up with a personality correlation coefficient of .70  (I don’t know what it is, that’s just a number I threw out).  But within that set of 1,000 pairs, you could have a number of twin pairs that in fact are dramatically different from their identically genetic sibling.  Even with that, the average correlation coefficient remains very high.  So as a rule, identical twins may be very close, but that does not mean they have to be.  And this my friends is the crux of the matter.

It is my opinion that we tend to follow our genes.  The overwhelming majority of individuals just go with the flow of their natural tendencies. I think that is a fact which has been clearly demonstrated.  Let’s face it, people are lazy.  But that does not mean we are slaves to our genes.  That does not mean we cannot overcome them.  Here is  just one example that I think most people will readily understand.

Weight – this is an area where opinions run high, but it is clearly something under the control of our behavior.  There are individuals who can eat like a horse and never put on excess weight.  There are others who without doubt have to be very careful or they balloon up rapidly.

I tend to the slim side genetically and thus it is much easier for me to lose weight than most other people.  In fact, I had to abuse my body horribly to get fat.  Had I spent those 30 years eating normally and being normally active, I would have been a fairly slim person.  Instead I had to lose over 70 pounds to get back into shape about 10 years ago.  I immediately started the abuse again and went back up slowly, and it took a long time to overcome my genetic tendency to be slim both times.

I know other people who tend to be heavy and pack on the weight.  And yet, through consistent effort they have gotten themselves into decent shape.  A couple of them have achieved superior fitness.  There are literally millions of example of both directions.

Still, if you study the genetic tendencies of the population as a whole, you will find that, as a whole, the population is ruled by its genes for weight.  Within that whole, there are millions of example of people overcoming their genetic tendencies.  The same thing would apply to all genetic tendencies to greater or lesser degrees depending on the trait.

The conclusion here is that you are not a slave to your genes.  You are responsible.  Just because most people don’t bother to overcome their genes, doesn’t mean that they or you are a slave to them.  Yes, it may be easier for me to lose weight and keep it off than it is for you, but we both can do it.  Just because nature dealt you a different hand does not mean it is not within your power to change, nor does it absolve you of your responsibilities.  There is without doubt many genetic traits that make it easier for you to do something than it is for me.  I can’t even draw decent stick people and my wife draws naturally and easily.  However, if I put my mind to it and tried, I could learn to draw like her.

You can do whatever you want so get off your butt and do it.  Stop blaming your genes for your problems because that is not the whole picture.  You can do it, you have just chosen not to because it is hard.  This may take away your convenient excuse, but I choose to look at it the other way.  To me, the fact that we can overcome our genetic tendencies opens up a world of boundless possibility.