When it comes to the nature vs nurture debate social scientists take Which of the following positions?

You got your green eyes from your mother and your freckles from your father—but where did you get your thrill-seeking personality and talent for singing? Did you learn these things from your parents or was it predetermined by your genes? While it's clear that physical characteristics are hereditary, the genetic waters get a bit murkier when it comes to an individual's behavior, intelligence, and personality. Ultimately, the old argument of nature versus nurture has never really had a clear winner. While we don't really know how much of our personality is determined by our DNA and how much by our life experience, we do know that both play a part.

The use of the terms "nature" and "nurture" as convenient catch-phrases for the roles of heredity and environment in human development can be traced back to 13th-century France. In simplest terms, some scientists believe people behave as they do according to genetic predispositions or even "animal instincts," which is known as the "nature" theory of human behavior, while others believe people think and behave in certain ways because they are taught to do so. This is known as the "nurture" theory of human behavior.

Fast-growing understanding of the human genome has made it clear that both sides of the debate have merit. Nature endows us with inborn abilities and traits. Nurture takes these genetic tendencies and molds them as we learn and mature. End of story, right? Nope. The "nature vs. nurture" argument rages on as scientists debate how much of who we are is shaped by genetic factors and how much is a result of environmental factors.

Scientists have known for years that traits such as eye color and hair color are determined by specific genes encoded in each human cell. The nature theory takes things a step further by suggesting that abstract traits such as intelligence, personality, aggression, and sexual orientation can also be encoded in an individual's DNA. The search for "behavioral" genes is the source of constant dispute as some fear that genetic arguments will be used to excuse criminal acts or justify antisocial behavior.

Perhaps the most controversial topic up for debate is whether or not there's such a thing as a "gay gene." Some argue that if such genetic coding does indeed exist, that would mean genes play at least some role in our sexual orientation.

In an April 1998 LIFE magazine article titled, "Were You Born That Way?" author George Howe Colt claimed that "new studies show it's mostly in your genes." However, the issue was far from settled. Critics pointed out that the studies on which the author and like-minded theorists based their findings used insufficient data and too narrow a definition of same-sex orientation. Later research, based on a more conclusive study of a broader population sample reached different conclusions, including a 2018 groundbreaking study (the largest of its kind do date) co-conducted by the Broad Institute in Cambridge, Massachusetts, and Harvard Medical School in Boston that looked at the possible links of DNA and homosexual behavior.

This study determined that there were four genetic variables located on chromosomes seven, 11, 12, and 15, that do seem to have some correlation in same-sex attraction (two of these factors are specific only to males). However, in an October 2018 interview with Science, the study’s chief author, Andrea Ganna, denied the existence of a “gay gene” per se, explaining: “Rather, ‘nonheterosexuality’ is in part influenced by many tiny genetic effects.” Ganna went to say that researchers had yet to establish the correlation between the variants they’d identified and actual genes. “It’s an intriguing signal. We know almost nothing about the genetics of sexual behavior, so anywhere is a good place to start,” he admitted, however, the final takeaway was that the four genetic variants could not be relied on as predictors of sexual orientation.

While not totally discounting that genetic tendency may exist, supporters of the nurture theory conclude that, ultimately, they don't matter. They believe our behavioral traits are defined solely by the environmental factors that affect our upbringing. Studies on infant and child temperament have revealed the most compelling arguments for the nurture theory.

American psychologist John Watson, a strong proponent of environmental learning, demonstrated that the acquisition of a phobia could be explained by classical conditioning. While at Johns Hopkins University, Watson conducted a series of experiments on a nine-month-old orphaned infant named Albert. Using methods similar to those employed by Russian physiologist Ivan Pavlov with dogs, Watson conditioned the baby to make certain associations based on paired stimuli. Every time the child was given a certain object, it was accompanied by a loud, frightening noise. Eventually, the child learned to associate the object with fear, whether the noise was present or not. The results of Watson's study were published in the February 1920 edition of the Journal of Experimental Psychology.

"Give me a dozen healthy infants, well-formed, and my own specified world to bring them up in and I'll guarantee to take any one at random and train him to become any type of specialist I might select ... regardless of his talents, penchants, tendencies, abilities, vocations and race of his ancestors."

Harvard psychologist B. F. Skinner's early experiments produced pigeons that could dance, do figure-eights, and play tennis. Today Skinner is known as the father of behavioral science. Skinner eventually went on to prove that human behavior could be conditioned in much the same way as animals.

If genetics didn't play a part in the development of our personalities, then it follows that fraternal twins reared under the same conditions would be alike regardless of differences in their genes. Studies show, however, that while fraternal twins do more closely resemble one another than non-twin siblings, they also exhibit striking similarities when reared apart from the twin sibling, much in the same way that identical twins raised separately often grow up with many (but not all) similar personality traits.

If the environment doesn't play a part in determining an individual's traits and behaviors, then identical twins should, theoretically, be the same in all respects, even if reared separately. However, while studies show that identical twins are never exactly alike, they are remarkably similar in most respects. That said, in "Happy Families: A Twin Study of Humour," a 2000 study published by faculty at the Twin Research and Genetic Epidemiology Unit at St. Thomas' Hospital in London, researchers concluded that a sense of humor is a learned trait influenced by family and cultural environment, rather than any genetic predetermination.

So, is the way we behave ingrained before we're born, or does it develop over time in response to our experiences? Researchers on both sides of the "nature versus nurture" debate agree that the link between a gene and behavior is not the same as cause and effect. While a gene may increase the likelihood that you'll behave in a particular way, it does not ultimately predetermine behavior. So, rather than being a case of "either/or," it's likely that whatever personality we develop is due to a combination of both nature and nurture.

The nature vs. nurture debate is the scientific, cultural, and philosophical debate about whether human culture, behavior, and personality are caused primarily by nature or nurture.

Nature is often defined in this debate as genetic or hormone-based behaviors, traits, and dispositions, while nurture is most commonly defined as environment, culture, and experience.

History of the Nature vs. Nurture Debate

The nature vs. nurture debate is an ongoing one. The modern debate often centers around the effect genes have on human disposition as opposed to the influences that early environment and development might have. As culture changes, so have popular understandings of this debate. In the 1960s, for example, psychologists—and pop culture in general—were heavily influenced by the theories of behaviorism. This theory led to the widespread belief that human personality is primarily influenced by experience and training. It was during this time that researcher John Money attempted to demonstrate that gender was a product of early conditioning by raising a boy, whose circumcision was botched, as a girl. His experiment seemed successful in the beginning but ultimately was a failure.

In recent years, the nature side of the debate has gained more attention, with headlines trumpeting newly discovered genes for virtually every behavior. Evolutionary psychology and sociobiology are two branches of science that attempt to demonstrate the evolutionary roots of human behavior. Books authored by scientists in these fields are extremely popular. However, critics still emphasize the important role of early childhood environment, development, and cultural influences. Many have argued that sociobiology and evolutionary psychology are deterministic pseudosciences.

Twin and Identical Twin Studies

Several studies done on twins separated shortly after birth reveal that genetics do play a significant role in the development of certain personality characteristics, sexual orientation, and religiosity. The bond between identical twins was also suggested to be genetic by these studies, as 80% of identical twins reported that they felt closer to their twin than they did to their closest friends, despite having just met their twin.

One study also suggested that genetics play a significant role in the development of personality: Environment had little effect on personality when twins were raised together, though it did have an effect when they were raised apart.

How Nature Affects Mental Health

While nature, or genetics, has been proven to be an important factor in the development of some mental health conditions, such as schizophrenia, bipolar, and major depression, the development of mental illness is not entirely genetic. Nature, or genetics and disposition, has been proven to be an important factor in the development of some mental health conditions, such as schizophrenia, bipolar, and major depression. Bipolar, for example, is four to six times more likely to develop when there is a family history of the condition. However, although the importance of genetic factors cannot be denied, the development of mental illness is not entirely genetic. For example, identical twins share their genes, yet if one twin develops schizophrenia, research shows the other twin only has a 50% chance of also developing the condition. This indicates that nature, while it plays an important part, is not the only contributing factor.

Another area where researchers may place more emphasis on nature than on nurture is that of addictions. Research indicates that alcohol addiction, for example, can recur in families and that certain genes may influence how alcohol tastes and the way it affects the body.

How Nurture Affects Mental Health

Certain genetic factors may create a predisposition for a particular illness, but the probability that a person develops that illness depends in part on environment (nurture). When a genetic variant indicates the possibility of developing a mental illness, this information can be used to direct positive (nurturing) behavior in such a way that the condition may not develop or may develop with less severity.

James Fallon, a neuroscientist who discovered that he had the brain of a psychopath, has stated that he believes growing up in a nurturing and loving environment helped him become a successful adult and may have been effective at preventing him from fully developing traits of psychopathy. Similarly, the basis for addiction is not thought to be entirely genetic by most researchers. Environmental aspects, such as the habits of parents, friends, or a partner, might also be significant factors contributing to the development of an addiction. A genetic predisposition to alcohol addiction may be far more significant if one is routinely exposed to binge drinking or other forms of alcohol abuse and comes to view this as normal alcohol use.

Researchers at the University of Liverpool recently found that while a family history of mental health conditions was the second strongest predictor of mental illness, the strongest predictor was in fact life events and experiences, such as childhood bullying, abuse, or other trauma. This supports the idea that nurture plays significant role in the development of mental health issues.

Nature vs. Nurture in Therapy

For example, using medication to treat a mental health issue may be a primarily nature-based approach, while behavioral therapy, which stems from behaviorist psychology, addresses a person’s upbringing and conditioning and takes a nurture-based point of view. Meanwhile, therapies based in cognitive psychology may be more likely to address the effects of both nature and nurture.

It is possible to find a therapist who takes a more nature or nurture-based approach to treatment. However, many therapists today consider multiple factors, including how the nature and nurture work together, during a session.

How Nature and Nurture Interact

Many scientists eschew the nature vs. nurture debate by emphasizing “nature x nurture.” In this schema, nature and nurture are inseparable. Some genes, for example, cannot be activated without certain environmental inputs. The development of vision is a prime example of this. People cannot develop normal sight without exposure to visual stimuli.

Similarly, some environmental inputs may be undermined by some genes. For example, some lifelong smokers may never experience smoking-related illnesses, and this may be due at least in part to their genes. Environmental toxins may alter the expression of some genes, and genes for many behaviors presumed to have a genetic basis have not been discovered.

Developmental systems theory, among other theories, presents an alternative to this debate that does not require scientists to advocate either for nature or nurture.

References:

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Last Updated: 09-28-2018