Let me call it the
GI-world. Humanity is leaving an era in which the letters “G.I.” generally evoked soldiers of the United States Army and airmen of the United States Army Air Forces. We are now moving slowly but surely into a new era in which those same two letters are likely to be used to designate
Genetic Inheritance: that’s to say, the part of human behavior that is derived more from Nature than from Nurture. The stuff that happened to be written already on the slate when we were born.
Observers often think it would be nice to believe that our slates are blank at the moment of our birth, and that children then meet up with countless real-world experiences enabling them to extend and enrich the writing on their personal slates. This blank-slate vision might be partly valid, but researchers discovered cases of identical twins, brought up in worlds apart, who adopted highly similar behaviors, suggesting that fragments of their DNA code were apparently duplicated.
Commonsense often makes us imagine that such afflictions as alcoholism or insanity might indeed be present “in the family”, meaning that the offspring of afflicted ancestors might indeed have an inherited tendency to fall into drinking or madness. While it’s extremely difficult to prove that this might be true, many observers feel that human behavior can be the outcome of a subtle mixture of Nature and Nurture. It’s possibly what a French humorist referred to as Nightingale Pastry. The stuffing is obtained by mixing together nightingale meat and horse meat in equal proportions: the flesh of one nightingale mixed with the flesh of one horse. In the Nature versus Nurture context, it’s still hard to determine whether the code already present on the slate was a huge horse or rather a tiny nightingale. No doubt a bit of both.
I believe personally that, in the future GI-world, a new class of investigators will examine simultaneously both the horse and the nightingale. For example, if both a mother and her daughter manifest symptoms of the kind designated as bipolar disease, then they might envisage the possibility that the daughter inherited this disorder from her mother. In order to form an opinion on this question, other individuals on the patient’s genealogical tree might be brought into the picture. Have comparable behavioral characteristics been observed at several places on the family tree ?
DNA-based investigations have revolutionized many aspects of our existence. At the modest level of my family-history research, a couple of trivial Y-chromosome tests enabled me to confirm the identity of one of my paternal great-grandfathers:
Chromosomes reveal the truth.
Ernest Skyvington [1891-1985] between his parents in London. My grandfather could never tell me what had happened to his father.
Sooner or later, in tomorrow’s GI-world, whenever we’re confronted with striking cases of weird behavior inside the family, observers will not be unduly surprised if observers decide to browse through both genealogical and biological data of all kinds. Pluridisciplinary research of that kid will appear to observers as no less unusual than, say, conventional psychoanalysis or psychotherapeutics.