Influences on Infant Temperament

Children are born each day and each child is different from the next. Parents often notice individual characteristics in these small children. The question has been raised many times as to what affects these individual temperaments that make us all so different from each other. The nature versus nurture debate is often brought up. Instead of focusing on just one of these, we need to focus on both sides. Much of our individual temperament at birth is due to genetics (nature), but much of it is also because of our surrounding environment during our prenatal development (nurture).

Genetic Inheritance

In talking about where our temperaments come from, let us first look at our genetics. When a child is conceived, that child inherits 23 chromosomes from each parent (Lamb, Bornstein, Teti, 2002). Therefore, they inherit genetics from each parent. This genetic makeup can be a factor in the type of temperament that child has.

Studies on twins have been done where the researchers compared identical twins with fraternal, or non-identical twins. The identical twins share 100% of their genes, whereas fraternal twins only share around 50% of their genes, just as normal siblings do (Lamb et al., 2002). The studies found that the identical twins had similar temperamental attributes such as their activity level and their irritability. The fraternal twins did not show as many similarities to each other in their temperaments (Shaffer, 2005). From these studies, researchers have determined that heredity plays an important role in a person's individual temperament.

Environmental Influence

Another important factor in the temperament of infants is the environmental influence put on infants. In one 1992 study it was found that Chinese American and Japanese American babies were less perturbable, were better at soothing themselves, and experienced less change in arousal state than European American babies (Lamb et al., 2002).

Another environmental influence on temperament is the type of child rearing that parents use. For instance, babies that cry a lot and do not adapt well can often become more calm and adaptable if they have calm parents that require them to follow certain rules (Shaffer, 2005). This is a great example of the influence of environment because it shows that even when an infant comes with a certain temperament, that temperament can be influenced and changed with help from an outside source.

Another example of an environmental factor that affects infant temperament is the amount of stress a mother experiences pre-natally. In a study published in 2005 it was found that mothers who experienced more prenatal stress found that their infants were more fearful, more negatively reactive, and they reacted more overall. These mothers also found that their infants seemed more distressed, and they smiled and laughed less (Pesonen, Raikkonen, Strandberg, Jarvenpaa). This study seems to be good evidence that genetics are not the only thing that affect infant temperament. The actions of outside individuals, in this case the mother, also affect an infant's temperament.

Putting It All Together

When infants are first born they are new and untouched by a lot of outside influences. They do come with the genetics given them, but they are also new and open to the new influences of their environment. When a child is first born, it seems difficult to specifically identify what temperaments are caused by what factors. For example, it would be impossible to tell if a child is cranky because they got cranky genes, or if they are cranky because the mom was really stressed during pregnancy. It would be almost impossible to determine what caused the crankiness. What is important to understand, is that both of these factors, namely genetics, and environment all have an influence on an infant's temperament. Each of these can effect the personality development of a child. However, though they can influence, they do not always accurately predict the outcome. A cranky child may develop to be a very calm and kind child. One of the most important things to remember in discussing temperament is that all people, regardless of their genetics and environment, have the ability to choose their actions.

Conclusion

Temperaments differ between each infant and they are influenced by many factors. Genetics and environment, both influence the temperament that is manifested in the flesh. It is impossible to separate the two because they are interconnected. Neither of these factors seems to be the win-all solution to understanding temperament, but they are important to recognize and acknowledge. In having this information, perhaps we can begin to better understand the children around us.

References

Lamb, M.E., Bornstein, M.H., Teti, D.M. (2002). Development in Infancy. New Jersey:

Lawrence Erlbaum Associates, Publishers.

Pesonen, A., Raikkonena, K., Strandberg T.E., Jarvenpaa, A. (2005). Continuity of maternal

stress from the pre- to the postnatal period: associations with infant's positive, negative and

overall temperamental reactivity. Infant Behavior and Development, 28, 36-47.

Shaffer, D.R. (2005). Social and Personality Development 5^th Edition. Belmont, California:

Thomson Wadsworth.