We always think that what
derives a human development? Are genetic or environmental
factors more important determinants of development? If both nature and nurture
play major roles.... how do they work together?
Let’s find that what these two
terms literally means. Nature refers to the individual's inherited
predispositions while nurture refers to the influences on the individual
of the social and cultural environment, particularly the family and the community
and of the individual's experiences. Most developmentalists would consider four
theoretical perspective to understand the influences of these three sources i.e.
culture, environment and biology in the domain of development.
In the lens of psychodynamic, a child moves through a series of stages, where one confronts with conflict between biological drives and social expectations. The way in which these conflicts get resolved determines the one's ability to learn, to get along with others and to cope with the anxiety. Though many individuals contributed to this perspective but two names are especially known for the same: Sigmund Freud, founder of the psychoanalytic movement and Erik Erikson. While Social Learning Theories focused on the role of modeling, or observational learning in the development of behavior. By the 1950s, social learning theory had become the major area to focus in research of child development. On other side, constructivist approach discussed through Piaget's lens that cognitive development results from children's active construction of reality based on their experiences with the world. Along with this, sociocultural theory, associated with the Vygotsky that emphasizes on the influences of culture on development.
Now, moving further there has
been a discussion that how nature and nurture interacts?
Let's understand with some examples... In physical growth, this is a
strongly canalized process as genes influence growth by controlling the body’s
production of and sensitivity to hormones. Sometimes mutations disrupt this
process, leading to deviations in physical size. Occasionally, a mutation
becomes widespread in a population. Genetic makeup also affects body
weight, since the weights of adopted children correlate more strongly with
those of their biological than adoptive parents (Stunkard, 1988) but
environment and culture also affects the physical growth like physical health
and survival itself depends on good care. E.G., Teratogens- environmental
agents that increase risk of deviations in normal development and can lead to serious
abnormalities or death. Such as nine year old Jairo Yumbolives in the Amazon
rainforest of Ecuador where vast quantities of petroleum waste were dumped in
the 1980s which continue to contaminate ground and water. It is likely that
prenatal exposure to such toxic waste caused his birth deformed hand. On the
other hand example of Lactose Tolerance one can see the co-evolution of biology
and culture. Lactose tolerance is the ability to digest fresh milk. Pastoral
nomads in the Middle East and Africa are an example. Hunger and thirst were
probably very common among these groups, so animals that had been originally
domesticated for meat became a source of food and drink in the form of
fresh milk, in these "dairying cultures” those with the variants lactose
able were more likely to survive and have children, thus passing on the
genetic capacity for digesting milk. So, one can say there physical growth not influence by heredity but environment and culture as well.
Language, in Chomsky's
LAD (Language Acquisition Device) is an innate system for picking up language
that permits children, as soon as they have acquired sufficient vocabulary to
combine words into grammatically consistent, novel utterance and to understand
the meaning of sentence they hear. In 1876, immigrants from China, Japan,
Korea, Philippines, Puerto Rico and Portugal came to Hawaii to get work, there
were no dominant language exist to support interaction among them, then
Hawaiian Pidgin English emerged, as a communication system with a minimal
vocabulary and grammar that permitted new immigrants to "get by” in
everyday life. So, language is not only considered as innate but it also has
influences of culture and environment.
Androgen hormones are related
to aggression in animals and they are also believed to play a role in humans,
but we also understand that child rearing practices and strife ridden families
promote aggressive behavior. In one study, higher estrogens and androgens were
linked to more frequent expressions of anger by adolescent girls in a
laboratory discussion session with their parents. Furthermore, arguing between
husband and wife, although stimulating aggression among all family
members, more often triggers hostility in children. Thus, both environment and
biology affects aggression.
Heritability supports a moderate role for heredity in IQ individual differences. Kinship studies
comparing IQ co-relations of identical and fraternal twins indicate that the
contribution of heredity strengthens with development. Along With this
environment also influences intelligence. In study, James Flynn (2001), found that
from 1930 to the present, IQ's have increased steadily in industrialized
nations due to improved nutrition, education and technological innovations
(including TV and Computers), more stimulating world and greater test taking
motivation may contribute to better reasoning ability of each successive
generations, but there are some aspects
where these influences varies in identity development. While cultural and environmental
have more influence in the formation of identity than heredity, on other side, in
gender stereotyping the heredity and cultural have equal contribution.
Sometimes heredity play major
role, sometimes culture and environment, but all these three are complementary
and supplementary to each other. All of them are essential for the development.
Hence, any trait of the individual is the product of heredity, culture and
environment.
References:
- Lightfoot, Lynthia, Cole, M. and Cole, S.R., The Development of Children, Worth Publishers, 2009.
- Berk, Laura, Child Development, 2009, 7th edition.
