Why are people the way that they are? This is not just one of the central questions of psychology; it is one of the ancient questions of life. Why are some people happy most of the time? Why do others seem sad most of the time? All of these questions poke at the heart of what makes a person the way that they are. In psychology this is known as the nature/nurture controversy. The nature/nurture controversy has been one of the central questions of psychology since the founding of the discipline. The answer of which is more powerful in shaping us—nature or nurture-0-lies at the heart of who we are.
Why a person is the way that they are basically boils down to two causes. It is either their DNA which dictates their disposition, or it is their environment that shapes them. An extreme proponent of the nature argument would say that 100% of the reason a person is they way that they are boils down to their DNA. On the other end of that extreme would be a position that believes 100% of the way a person is has to due with their nature. Most psychologists fall somewhere in the middle and believe that it is a combination of things that lead to the formation of an individual’s disposition and personality.
Recently, a number of studies have begun to shed light on the controversy of what—nature or nurture—plays which roles in shaping us. Michael Rutter is a psychologist who has studied this issue. According to him, over the last half century, there has been an explosion of knowledge on the effects of nature, nurture, and developmental process” (Rutter, p. 1, 2002). It is one of the most carefully studied and reviewed questions of psychology.
More knowledge though, does not always lead to more understanding. Rutter writes that, “both the pages of scientific journals and the media have been full of the most absurd confrontations and polarizations” (Rutter, p. 1, 2002). What Rutter realizes is that the issue is complex, and that there is a powerful combination of environment and genes interacting with each other to shape the disposition of an individual. As my own mother will tell people, offering anecdotal evidence for the nature side, all of her children from the time that they were in the womb had unique personalities. Some babies, stayed up in the womb kicking, while others slept. After they were born, the ones who stayed up kicking were the kids who had more trouble sleeping at night. This anecdotal evidence points to the genes shaping this particular behavior and not the environment, which was the same for all of her offspring.
This evidence seems to point to nature playing a powerful role in development and disposition. Robert Plomin, a prominent geneticist and psychologist ascribes much of how people end up being shaped to their DNA. According to him, “Behavioral genetic research has shown that genetics is important throughout psychology, make children growing up in the same family different.” (Siegel-Itzkovich, pg. 1, 2012). A large part of what Plomin’s work consists of is figuring out why children growing up in the same family often are very different. This certainly seems to score another point for nature within the debate. Children from the same family very often lead much different lives, though they come from a very similar environment.
An example of children coming from the same home environment, but being reared very differently is the classic case now known as “The Case of the Boy Who Became A Girl.” A woman named Janet Reimer had two twin boys whose names were Bruce and Brian. During the course of circumcision, Bruce’s penis was destroyed. At the time Reimer became aware of work that was being done in the Psychology Department of John Hopkins University. The research had to do with a theory that environmental variables, not genes, determined a child's gender identity. Schillo, p. 4, 2004). This idea stood in contrast to those psychologist who believed that DNA determined gender. Since a vagina is much easier to construct than a penis, the Reimer family decided to have a vagina constructed for Bruce and to raise him as a girl. At 21 months the family had a sex change done on Bruce and decided not to tell him that he had been born a boy, so that they could raise “her” as a girl.
Bruce was now called Brenda. And according to theories that believe that nurture is more important to nature, Brenda should have grown up to accept her gender as a female. Though Brenda received estrogen treatments, while she was raised as a girl, her male identity was engrained deeply in who she was when she was born a male. She rejected her identity as a female. In her fantasies she saw herself as a “big guy” with “lots of muscles” (Schillo, pg. 4, 2004). Brenda became unmanageable as a teenager. After two suicide attempts, her doctors and her mother so no other recourse but to allow her to switch back to a him. Brenda then became David, went on to have relations with women and live a life as a man.
This case shows that nature powerfully forms us. But this does not however completely discount the role of nurture, which is also very important in shaping who we are. University of Iowa psychologist Mark S. Blumberg frames the argument this way, “You can’t break it down and say there’s a gene for being jealous, there’s a gene for being depressed, there’s a gene for being gay. Those types of statements are simplistic and misleading” (Blumberg, pg 79, 2009).
Evolution in other species shows that many animals are able to survive in the world acting completely on instinct. Some animals never even interact with their parents and therefore have no one to “shape their behavior.” Instead their behavior comes prepackaged in their genes.
It has also been pointed out that while chimpanzees share 90% of our genes, they certainly do not share 90% of our behavior. So the question is not “is it nature and nurture that determines why a person is the way that they are?” The real question that psychologists who are studying this question today is, “To what degree does the complex interaction between DNA and environment shape the individual?”
What scientists are attempting to do today is to show what is doing what. The experiments that are conducted are difficult because it is never easy to say what exactly is at work on the individual—nature or nurture? The answer is neither, and both working together.
References:
John P. Spencer, Mark S. Blumberg, Bob McMurray, Scott R. Robinson, Larissa K. Samuelson, and J. Bruce Tomblin. Short Arms and Talking Eggs: Why We Should No Longer Abide the Nativist-Empiricist Debate. Child Development Perspectives, 2009; 3 (2)
"Nature versus Nurture: Human personality." www.JPost.com. N.p., n.d. Web. 11 Feb. 2014. <http://www.jpost.com/Health-and-Science/Nature-versus-Nurture-Human-
Rutter, Michael. "Nature, Nurture and Development." Child Development. N.p., 5 Feb. 2002. Web. 10 Feb. 2014. <http://www.psy.miami.edu/faculty/dmessing
Schillo, Keith. "Nature or Nurture: The Case of the Boy Who Became a Girl." SUNY College. N.p., n.d. Web. 11 Feb. 2014. <http://sciencecases.lib.buffalo.edu/cs/files/gend
