The Probabilistic Epigenesis model of developmental outcomes assumes that individuals of the same genotype can have different neural and behavioral outcomes according to the dissimilarity of their relevant life experiences...
- Gilbert Gottlieb -
Bet you thought I meant "Physical Education". No, sorry. I meant "Probabilistic Epigenesis" or PE for short. For quite some time now myself and a host of others in the field of psychology, psychiatry, and biology to name just a smidgeon of the various professions involved, maintain the view that human development occurs as a combination of "nature and nurture". If you recall, the "nature-nurture" debate focuses on how much of who we are is a result of "nature" - our biology, genetics, destiny, what which is predetermined, versus "nurture" - our environment, culture, family, learning, and the choices we make. Meaning, that higher organisms such as us, develop, physically and mentally, through some combination of what we inherited through our gene pool, and through learning which is a product of what we acquired from our environment. Our environment is everything outside of ourselves. It could be within our house - what we picked up from how we were raised by our caregivers and those that shared our living space, or it could be within our community, state, continent or world - what we learned from just being on the planet. What we did on Saturday night and with whom, where we go to school, who we associate with, etc. You get the point. This thinking was not always the case...
While genesis generally refers to the origins or beginning of something, epigenesis refers to the stages or steps that constitute the beginning of something. Probabilistic refers to the statistical probability or causality of something. In other words, what is the likelihood of such a thing happening or occuring. Taken together, PE is a model, made known by the wonderful experimental psychologist Gilbert Gottlieb who died just last year. According to Gottlieb and the backbone of PE, it is a developmental model of how we become the human beings we are. PE resurrects the old nature-nurture thing by stating that there is a bidirectionality between our genes and our environment. Not only does our biology impact our environment (i.e. our intelligence and physical appearance will impact our profession and mate selection), but our environment impacts our biology (i.e. our profession can in turn impact our intelligence and our mate selection can certainly impact upon our physical appearance and our longevity!) Yes it does.
Phenotypically speaking (that would be my physical appearance that is genetically expressed), I have blonde hair blue eyes and very pale skin. Because of this color combination, or lack there-of as it pertains to my somewhat absence of skin color, I cannot tolerate the heat, but do fairly well in cold weather. With the exception of my mother, no one else in my family has light hair eyes or skin. My family tolerate and in fact prefer warmer weather and enjoy a good bask in the sun. I prefer the snow, skiing, and melt in the summer months. As it relates to PE and the issue of bidirectionality, it means that the majority of my family will live in warmer climates and I will not. I will live in cooler climates which in turn means that my genetics will in part determine my choice of climate preference and hence where my offspring and future generations will live. This is a prime example of my genetics effecting me and me in turn impacting my genetics, or the case for bidirectionality.
According to Gottlieb, there are 4 levels of analysis that effect PE: genetic activity, behavior, neural activity, and the external environment. Using the example above, my phenotypic expression which is genetically determined, my behavior (avoiding the sun and hot locations), my external environment (where I choose to live), will all impact future generations and the neural activity produced as a result (i.e., all of the neurological correlates that go hand-in-hand with living in colder climates and having light coloring such as higher sensitivity to physical pain and greater possibility of developing osteoporosis). We know and as Gottlieb points out, "there is considerable evidence that genetic activity is influenced by neural, behavioral and external environmental events..." (Gottlieb, 2007, p.2).
In all that I state, rather ad nauseum, I maintain that sex addiction is a disorder - a progressive disease process - that is in part secondary to early childhood trauma (s.f my earlier posts in this blog). It is something that occurs as a result of certain types of toxc childhood such that the limbic system is impacted and maldevelopes which in turn impacts and alters the predominantly right prefrontal cortex. Sexual addiction is a prime example of a probabilistic epigenesis impacting the developing human organism during critical periods of neurodevelopment. In sum, PE makes the case for the nature-nurture issue and the sustained impact that nurture (environmental events) can and does have on the developing nature of the human being.
Early childhood trauma, even when there is no physical involvement, can and does alter the limbic system and exceedingly important aspects of the frontal lobe. We know this to be true. Parents and caregivers most definitely effect, good and bad, the actual neural code of our developing brain - how we are raised can and does impact and alter the neural networks and neural nodes in our developing brain and sets us up as adults, good or bad, for the life we will eventually lead - good and bad. When things go well environmentally, when we are lucky enough to be the recipient of a decent, loving, and nurturing household, our brains will thrive, as will our body, all things being equal, and we will more likely reach our genetically endowed limits. Otherwise, the reverse, having come from an abusive or malignant or toxic household, can and will limit our ability to thrive, to succeed, to achieve, and to be healthy. And in some cases, depending upon the damage done, our ability to sustain the damage experienced, and the resultant pathology that is left in its wake, will visit us and stay until, when and if, we are able to make some changes, to the extent that it is possible.
The good news, PE is but one more example of a scientific explanation for why sex addiction is a preventable disease, and why we need, more than ever, to recognize it and take the necessary steps to do something about it. What, exactly, will be up to you.
As always, you are encouraged to join the conversation and let me (and others) know your thoughts...