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Why the Topic of Bioethics in Science
Classes?
A New Look at an Old Debate
by Carolyn Csongradi
"Nature"
And "Nurture" Interact In Sequential Stages:
Certain experiences are crucial to the maturing brain which develops
in a series of stages such that the success of the next developmental
stage depends upon the previous one. Our inherited nature is augmented
by appropriately timed stimulation and the results can be tested
behaviorally.
In the early 1900's, Piaget was
the best known proponent of the hypothesis that children are born
with few of the concepts possessed by an adolescent. His ideas
were based on a series of elegantly designed experiments which
studied how babies and young children acquired the concepts of
object, space, and cause and effect. He proposed that children
pass through a series of developmental stages where one stage
builds upon the other by a process of assimilation followed by
accommodation to the realities of the world. The process is largely
one of brain maturation with appropriately timed environmental
stimulation.
Piaget has been criticized for emphasizing a specific form of
thinking which is more relevant to Western cultures. Subsequent
experiments have demonstrated that individual stages are achieved
in a less step-wise, more continuous fashion over a wider range
of ages than he would have predicted. His theories do not always
generalize across different content areas. For instance, the same
child may show a grasp of the conservation of volume in one situation
but not in another.
Another way to look at the interaction between the developing
mind and environment has been to study the mother-infant bond.
The mother is often considered the infant's first experience with
an object from the world. During the 1930's Renee Spitz followed
by John Bowlby studied infant deaths in foundling homes and in
long term hospitalization. These sterile environments lacked visual
and tactile stimulation and although they had adequate care in
the strict sense, human contact was notably absent. A significant
percentage of these babies died in the first year. In the early
1950's Harry Harlow experimented with social isolation in newborn
monkeys which extended from birth to as long as one year. These
monkeys were severely socially impaired as a result of the isolation.
Such vulnerability was not detected when older animals were isolated.(17)
D.W. Winnicott, a 20th century British psychiatrist, coined the
term " good enough mother", theorizing that there was
never just an infant, but an infant-mother pair. Babies gain knowledge
about objects from their experiences with the mother. If young
children are deprived of a nurturing environment, such as in the
case of an alcoholic or abusive parent, infants learn that objects
come and go unpredictably. He believed this early exposure to
the concept of object permanence (or impermanence) continued to
influence how these children learned about other real world objects
in a skewed way through out their lives.(43) A colleague, Arnold Modell,
went one step further by stating the capacity to know and the
capacity to love are not separate functions.(22)
While the pre-programmed information for grasping, sucking and
orienting toward human faces are instinctual requirements for
Piaget's developmental theories, they may become impaired through
neglect and abuse by caregivers. Reality is constructed from what
we know and what we value as important from experiences occurring
at a very early age.
In the developmental model, natural selection has encouraged the
brain to be flexible at certain key periods rather than emphasizing
an assessment of the environment. The nature based model valued
receptors for gathering environmental information. The genes selecting
for brain plasticity were less important. While we might reasonably
expect to find a gene or genes for instinctual behaviors, the
full development of an individual would depend on being exposed
to certain stimuli, to establish the basic building blocks for
sequential development.
Nature and Nurture Continued:
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