For good or ill, I have, lately, been reading a great deal about genetics and its effects on our lives. As for the reason for this pursuit, I can only offer that I have spent many an hour of my life wondering just what I would be like if I had been raised by my genetic mother rather than my father and stepmother. While many would suggest that this is a fruitless inquiry which has no real - which is to say, honest - answer, for whatever reason, I cannot seem to leave it alone. Perhaps, if I share my angst, I can abandon this obvious "hangup" and move on to more fruitful endeavors. And, so, here is the attempt to do just that.

To re-flog a well-beaten horse, my parents abruptly separated and divorced when I was about 9 years old. Through a murky (to this day) series of events, I lived with my father and his mother for a time and my two sisters - one older and one younger - remained with (I almost typed "their mother") our mother for the remainder of their childhoods. I have no recollection of ever seeing my mother after the finality of the divorce, though I have to believe that is not entirely true. Likewise, I have no memory of sisters for the remainder of my childhood. Eventually, my father remarried and the three of us - father, stepmother and Junior - moved into a new house in suburbia. My sisters grew up with our mother in, as I have been told, slightly less opulent circumstances. My sisters became unwed teenage mothers; I became a physician.

This is where "the wonder of it all" comes in. If the situation was reversed or, if as is most often done, all the children were awarded to the mother, what would I be today? Given the rather bleak economic status that I have been lead to believe that my mother (who also remarried) and my sisters had in the years of my youth, I cannot accept that I would have gone to college, much less medical school. I cannot completely dismiss the notion but it seems unlikely. Since the man my mother married (by all accounts, a good, decent man) was a mechanic, I suspect that I might have gone into that trade. Possibly, today, I would know more about cars and engines than I do now, which is to say, nothing. I may have gotten a tattoo or developed a fondness for beer or hunting or even fishing. I may have become a biker or a criminal or a fan of Ultimate Fighting or a drug addict or, well, all sorts of "adventurous" possibilities.

But I don’t entirely fixate on the many possible negatives. Maybe I would have been less obsessive-compulsive, which would certainly infer I would not be giving this amount of thought to the question now under consideration. It would certainly be plausible to think I might be more open to new experiences, less cocky and a lot more humble. Most assuredly, for most who know me these would be, welcomed changes. Maybe I would have been more of an extrovert and be able to enjoy the company of people I might consider friends and less the hermit and borderline recluse I have long been. I am almost convinced I would not be the workaholic that I am today. I probably wouldn’t get up every morning (I literally mean every morning) at 5:00 and get to work in order to read or write or just think, alone. I might even be able to sit through an entire football game and enjoy the simple pleasure of doing absolutely nothing, something I am completely unable to do now.

From my reading on the subject, I have discovered that there are some interesting laws that come into play when I ponder the imponderable. Let us begin with the work summarized by Dr. Eric Turkheimer. He wrote:

"The nature-nurture debate is over. The bottom line is that everything is heritable, an outcome that has taken all sides of the nature-nurture debate by surprise. Irving Gottesman and I have suggested that the universal influence of genes on behavior be enshrined as the first law of behavior genetics (Turkheimer & Gottesman, 1991), and at the risk of naming laws that I can take no credit for discovering, it is worth stating the nearly unanimous results of behavior geneticsin a more formal manner.

• First Law: All human behavioral traits are heritable.
• Second Law: The effect of being raised in the same family is smaller than the effect of genes.
• Third Law: A substantial portion of the variation in complex human behavioral traits is not accounted for by the effects of genes or families."

Now that we have heard the adequately garbled science-speak, what is the good doctor actually saying? Well, in the First Law, he is positing that everything - from I.Q. to how much TV we watch, what books we read and which movies we prefer, the likelihood we divorce and the like - are all inherited. In the Second Law, he is saying that siblings reared in the same household under the same conditions vary in these behavioral traits (I.Q, etc.) to the exact same degree that siblings raised in different households do. A "shared environment" (the same household) has a almost no effect on our adult behaviors. The specific findings are easy enough to understand and are as follows:

• adult siblings are equally similar whether they grew up together or apart
• adoptive siblings in a shared household are no more similar than two people randomly plucked off the street
• identical twins are no more similar than one would expect from the effect of their shared genes; that is, they are equally alike whether reared together or in separate homes

Despite flying in the face of all the theories of parenting "Baby Einsteins" and the multibillion dollar industry for childhood toys to make a smart baby, the scientific evidence is now clear that little if anything (excepting, of course, gross child neglect and abuse) the parents are going to do will change later behavior in a given child.

In Law Three, we have the coup de gras: Genetics account for about 50% of our adult behaviors and capacities. The effect of the family environment is, optimistically, about 10%. And the "substantial portion not accounted for by the effects of genes or families" is 40-50% of the basis for our behavior. This nebulous set of circumstances are our "unique experiences" - that is, those not shared by siblings and unique to ourselves, alone. How we were cared for (or not cared for) when we were sick, beat up at school, made fun of by our peers, the particularly memorable spankings (they were more like "beatings" in my house, but that is neither here nor there) we were the beneficiaries of, the Christmas gift we did or didn’t get - all these (and thousands more) make up our set of unique experiences and shape about 40-50% of our adult behaviors.

So, where does all this information leave me. It peeks my imagination, actually. I imagine sometimes that I was an identical twin. And, like my sisters and I, my twin and I were abruptly separated around age 9 or 10 and went to live with one of our parents in different households. We were thereafter, reared completely apart and without any contact between us. One of us lived a typical middle-class life; one of us lived in poorer circumstances without a lot of emphasis on achievement or advancement. One of us read books and wrote about anything and everything that caught his eye; the other worked on cars with his stepfather and learned how things operated and were put together. One was supervised by a well-meaning but definitely alpha-male father; the other was raised in a matriarchal household with two sisters and a mother who loved him. One dreamed big dreams of a college, a successful career and a comfortable lifestyle; one dreamed of the day he would get his driver’s license and have his own car or, better, his own Harley-Davidson. Both were happy, in their own way, and lived to see their own families grow up and enter the world.

In my imagination, the twins are sitting - quite by chance - in the waiting room of the same office when they are in their late 50s, waiting to be seen for an appointment. They are the only ones in the waiting room. One has a full beard and is in a baseball cap and blue jeans; the other is in a sports coat and tie. One picks up a copy of National Geographic magazine; the other picks up Popular Mechanics. Both begin to read. They look up from their magazines, both at the same instant, and their eyes meet. For a moment, there is a hint of recognition in their eyes, though they really don’t look that much alike, even for identical twins. The look changes in a couple of seconds and the two brothers exchange a cordial smile and return to their magazines. A few moments later, one is called in for his appointment. The remaining twin does not recognize the name as he was reared under another. Just as the departing brother reaches back to close the door behind him, he glances again at his unknown brother and, for whatever reason, smiles again and nods goodbye. For a split second both faces seem to know, to recognize, that they are one and the same person but, at the same time, entirely different men. As the door closes, the brother left in the waiting room returns to his magazine. Inexplicably, he feels a strange sense of peace, a calmness. Something has changed in his life forever. He seems to understand, for the first time, that things happen for a reason and a purpose.

And, when all the anger, blame, guilt and regret is tossed into the wastebin (where it rightfully belongs), we come to realize that we are on this earth to be who we are destined to be and to make the best use of whatever gifts our genes, our circumstances and our unique experiences give to us. And that, gentle reader, is all anyone can expected of us.

More importantly, that is all we should expect of ourselves.