Nature vs Nurture

Allison Harris
Nature vs. Nuture
University of New Hampshire

For more than 50 years sane voices have searched for an answer to the everlasting debate of nature vs nurture. The debate causes quite a controversy, whether inherited genes or the environment influences and effects personality. Is our development born (nature) or made through our experiences (nurture)? Some believe that is strictly our genes; others believe it is the environment; while others believe that is a combination of both, our genes and the environment. In the 18th century, Locke claimed that individuals were born was a tabula rasa and only experience could establish mind, consciousness, and the self. Leibniz envisioned the self as a monad carrying with it knowledge of a basic understanding of the world (Macleod, 2007). The nature side of this debate argues that development is based on the genetic factors that one is born with. Those who adopt an extreme heredity position on the debate are known as nativists. Their basic assumption is that the characteristics of a human as a while are a product of evolution and that individual differences between people are due to each person’s unique genetic code. They also believe that maturation is responsible for characteristics and differences that are not seen at birth, but observed later in life. At the other end of the debate, lie the empiricists. Empiricists’ basic assumption is that at birth the human mind is a blank slate and as we grow and develop as a person, our “blank slate” is filled as a result of one’s personal experiences. Empiricists believe that the concept of maturation applies only to ones physical and biological maturation, and that it is how one is brought up that determines the psychological aspects of one’s development (Macleod, 2007). The traditional dichotomy of nature vs. nuture is commonly seen as a false dichotomy. Today it is largely agreed upon that nature and nurture are intimately cooperating to bring about adaptive behaviors. Many realize that genes and environment cooperate and interact synergistically. Therefore, instead of debating whether is it nature or nurture that determines development, the question has been reformulated to which factor is more important in determining development? Sandra Scarr and Kathleen McCartney proposed a theory of environmental effects on human development that emphasize the role of the genotype in determining not only which environments are experiences by individuals, but also which environments individuals seek for themselves. Scarr and McCartney claim that human experience and its effect on development depend primarily on the evolved nature of the human genone. The duo also argues that the genotype determines the organism’s responsiveness to environmental opportunities, therefore genotype large determines environmental effects on development. Scarr and McCartney propose that development is the result of nature and nurture, but that genes drive the experience. They distinguished among three kinds of genetic-environmental correlations: passive, reactive, and active. Passive influences result from the correlation between genetic characteristics of a child and the conditions provided by the child’s biological parent. Reactive influences result from environmental responses to individuals that are correlated with the child’s genotype. For example, the association between marital conflict and depression may reflect the tensions that arise when engaging with a depressed significant other, rather than a casual effect of marital conflict on risk for depression. Active influences refer to a tendency of individuals to select environments that may be compatible with their specific genotype. For example, individuals who are extroverts may seek of very different social environments than those who are shy. Therefore it is one’s genetic make up that determines the environment that they seek out. Twin and adoption studies provide a great deal of evidence in supporting these claims. Scarr and McCartney also back theory about passive genotype with studies of parental treatment of more than one child. Studies of responses that inividuals evoke from others support their ideas about evocative genotype, and finally active niche building studies support their theories of children selecting and building niches correlated with their talents (Scarr and McCartney, 1983). The authors are not claiming that is solely nature or nurture that explain cognitive development. They believe that both genes environments play a role in development, but that they have different roles. Scarr and McCartney concluded that genes direct the course of human experience, but experimental opportunities are also necessary for development. A research study was done by DeCasper and Fifer (1980) to determine when newborns can identify their mother’s voice. Language acquisition and sounds are very important during the last trimester of pregnancy to begin the process of mother-infant bonding. The results of the study showed that newborn babies less than three days old can distinguish their mother’s voice among other and try and mimic their mother’s voice if another female voice is nearby. The study consisted of ten newborns. A recording of their mother’s reading a Dr. Seuss book was used to test the infants and have them decipher their mother’s voice. The infants were places in a bed with headphones on and a nipple in their mouth. A baseline was then established to determine the relationship between the time elaspsed between the end of one burst of sucking and the beginning of the next. A separation in time was identified at a two second break in between sucks. The ten babies were then split into two groups of five. One group were given the opportunity to hear their mother’s voice if their sucking burst was greater than the baseline test. The conditions were reversed for the other group of infants. The experiment resulted with eight of ten newborns moving their heads in the direction of their mother’s voice. Therefore, it was determined that newborns can make a distinction between their mother’s voice and a stranger (DeCasper and Fifer, 1980). Sixteen newborns were the subjects in a second experiment done to validate the findings of the previous study. A descriptive stimulus was presented to the infants in the form of a tone, which lasted for four seconds. After the tone there was an period of silence for four seconds. For eight of the infants, “sucking bursts initiated during a tone period turned off the tone and produced the story read by the infant’s mother, whereas the sucking burst during the no-tone period produced a non-maternal voice” (DeCasper and Fifer, 1980). The other group of eight newborns received the opposite conditions. The results of the study showed that at the beginning not all of the infants responded to their mother’s voice, however as the study progressed the infants began to respond to their mother’s voice at an increased rate. This data represents that very young infants even with little contact with their mothers can distinguish their mother’s voice and work to replicate it. This experiment supports the nurture argument. It could be that an infant’s preference of their mother’s voice is innate and directly caused by the genes. However, the scientists in this experiment did not mention this as a possible explanation, leading one to believe that they are not specifically on either side of the nature vs. nurture argument. The nature vs. nurture argument can be traced back to the 13th century in France. However, by observing the studies done relating to the subject and looking at most scientists views on the subject today, it can be determined that both nature and nurture play a role in development. Nature endows us with inborn traits and abilities, nurture takes these genetic tendencies and molds them as we grow and mature. However, there is continued debate about which plays a larger role.

Work Cited
1. Decasper, A.J., & Fifer, W.P. (1980). Of human bonding: Newborns prefer their mother’s voices. Science, 208, 1174-1176.
2. McLeod, S. A. (2007). Nature Nurture in Psychology. Retrieved from http://www.simplypsychology.org/naturevsnurture.html
3. Scarr, S. & McCartney, K. (1983). How people make their own environments. A theory of genotype influences environment effects. Child Development, 54, 424-435.

Cited: 1. Decasper, A.J., & Fifer, W.P. (1980). Of human bonding: Newborns prefer their mother’s voices. Science, 208, 1174-1176. 2. McLeod, S. A. (2007). Nature Nurture in Psychology. Retrieved from http://www.simplypsychology.org/naturevsnurture.html 3. Scarr, S. & McCartney, K. (1983). How people make their own environments. A theory of genotype influences environment effects. Child Development, 54, 424-435.