An area of controversy in the life sciences relates to the
relative roles of genetics and the environment. Confusion commonly afflicts
politics. For example, early Communists glommed on to the discredited genetic
theory of “inheritance of acquired characteristics.” This theory holds that
changing a person’s attitude and behavior would somehow result in changes to
his or her genes, which would allow for genetic transmission of the changed
attitudes and behavior to his or her children. For this idea to be true,
outside influences on the brain would have to change the genes not only in
brains but also in the sex cells (sperm and egg cells). The idea was held in
ancient times by Hippocrates and Aristotle, but it gained scholarly imprimatur
with formal publication in 1809 by Jean-Baptiste Lamarck. In the 1930s, the
Russian president of the Soviet Academy of Agricultural Sciences, Trofim
Lysenko, applied the doctrine to Soviet agriculture with disastrous results. At
the same time, Soviet political leaders extended the mistaken doctrine to
inheritance of educational and social experiences; that is, changing human
nature by government policy. They expected that indoctrinating the current
generation in collectivism would genetically transfer collectivist attitudes
and behavior to all future generations. Cuba, North Korea, and China showed
that collectivism can be transferred culturally but not biologically.
In the United States, much
political angst arises from disputes over whether more effective educational
and social policies will succeed in lifting people out of poverty and
dysfunctional behaviors. When I was a child, I often heard the axiom, “You can
take the boy out of the country, but you can’t take the country out of the
boy.” Today, the corresponding axiom would seem to be, “You can take the boy
out of the ghetto, but you can’t take the ghetto out of the boy.” The reality
is that you can take the country or ghetto out of the boy, but this won’t
transfer to his children by his genes.
What we are now discovering is that
environment and experience affect the expression of genes. Whether or not genes
are accessible for readout often depends on the environment. People have
underestimated their capacity to sculpt their own brains, attitudes, and
behavior by controlling experiences that affect gene expression. Though people
may control to some extent how their own genes are expressed, there won’t be
any biological transfer to their heirs. Environmental and cultural influences
do of course transfer, so one’s heirs can be taught how to likewise exert
control over how their genes are expressed.
Having the right chemicals in the
right environment at the right time is believed by most scientists to be all
that is needed for creating life and shaping the mental life of the individual.
To them, life seems like a highly improbable occurrence. But it did happen, and
even more improbable, there may be a life force that sustains it.
Many scientists also think of the
brain’s conscious mind as an emergent property of brain function. Emergent
properties follow the rule that the whole is greater than the sum of its parts.
Another way of saying this is that the properties of the whole cannot be
predicted from what you know about the properties of the contributing parts.
Yet, paradoxically, most scientists believe that as they learn more and more
about less and less, they will somehow explain the whole.
Emergent properties apply both to
molecules in a primordial soup that generate simple living organisms and to the
87 billion or so neurons of a human brain that generate a conscious mind. A
physical world that can generate emergent properties is a mysterious and
magical world indeed.
What gets left out in such
consideration is the capacity for personal control over one’s biology, which is
an important theme. I contend that at the level of the individual person, mind
itself—especially conscious mind—is a major force of natural selection that
drives creation of mental capacity and character. The implications for daily
living could not be more profound. Accepting one’s biology and circumstance
breeds helplessness and fatalism. So, it boils down to one’s belief system.
Either you are “captain of your own ship, master of your own fate,” or you are
shackled by the belief that change is not possible. What you think and do
shapes your brain's function.
Excerpted from Mental Biology. The New Science of How the
Brain and Mind Relate, by W. R. Klemm. New York: Prometheus. See rave
reviews at WRKlemm.com, click on "author."
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