Experts have long argued over the nature-versus-nurture debate. What factors are most responsible for making people who they are? Members of the nature camp argue that genes are the biggest factor in shaping a person’s health, personality, and perhaps even his or her choices in life. Many of these experts believe that we are all hardwired from birth to be the adults we later become. Members of the nurture camp, on the other hand, argue that upbringing, environment, and life experiences are the most important factors in making us who we are. Based on their view, a factor such as growing up in a rural setting rather than in an urban one, for example, might easily shape the kind of person we become.

Genetic links to other diseases are not as easy to pinpoint. For example, studies have shown that early-onset Alzheimer’s, which can attack the brain in people as young as age thirty, is linked to genetic inheritance in most patients. However, experts believe that late-onset Alzheimer’s, which affects people over sixty years old, may be caused by a combination of genetic factors, health choices, and the environment.

In other words, there is plenty of gray area in the nature-versus-nurture debate even when the science of genetics is the main focus. In many cases, genetic inheritance—the nature side of the debate—cannot fully explain why certain health issues occur.

Also, physical features and health issues do not necessarily determine the more subtle aspects of the people we turn out to be. Think of the people in your school. Why are some students lazy while others work hard? Why are some well behaved while others get into trouble? Why are some students shy while others are more outgoing?

To gain insight into such questions, researchers in England recently studied a large sampling of both identical twins and non-identical twins from areas all across England. The goal of the study was to find out whether nature or nurture was more responsible for shaping people. Experts gathered data about the test subjects’ personality traits—forty-five types of traits in all—and then recorded that data on a map of England. The results of the study showed that in sixty percent of the country, children’s behavioral traits were linked more closely to genes than to their surroundings. So, as some experts reasoned, this proves that nature is a stronger force than nurture, right?

But there was a catch. The same study found that in London, England’s capital city, the test subjects’ environment played a stronger role than their genes. Experts think that the close proximity of families with diverse backgrounds in London’s urban setting may have strongly affected the test subjects’ personalities and behavior. For example, twin siblings raised in the same home may have chosen to associate with two entirely separate circles of friends. One sibling may have chosen to hang out with street gangs, while the other may have chosen to adopt a group of studious friends. This could shape the twins’ personalities and behavior in very different ways.

After reading the findings of the above study, it would be easy to say that the nature-versus-nurture debate is a draw. The study seems to suggest that genes control who some people become and environment controls who other people become. But, as one of the researchers on the project explains, the study has shown that it is a person’s environment that determines how the person’s genetic makeup reveals itself. So, while nature and nurture work together to some degree, at least one group of experts believes it is nurture—the environment—that has the upper hand in shaping our unique personalities.

How do paragraphs 1 and 2 contribute to the structure of the article as a whole?

a
They describe a problem and give a possible solution that the author will explain in detail.
b
They introduce an argument that the author will then support with several reasons.
c
They provide two opposing opinions that the author will continue to analyze.
d
They present a sequence of events caused by a situation that the author will later describe.

How do paragraphs 6 and 7 contribute to the author’s development of ideas in the article?

a
They show that genes have more influence than environment.
b
They show that the nature-versus-nurture debate is complicated.
c
They suggest that environmental factors may cause certain illnesses.
d
They say that the nature-versus-nurture debate is a pointless exercise.