Is Human Behavior Influenced by Genes or Environment


Nature vs nurture is a popular cultural catch phrase used to describe an ongoing argument that dates back to the 13th century. This debate deals with the roles that heredity and environment play in human development. The basic argument has one side contending the people act as they do because of genetic predisposition or animal instinct. The other side, however, says some so called predispositions are in fact learned behavior or environmentally influenced.

Present day studies into the human genome makes it clear the both sides are somewhat correct. Nature, heredity or genetics, in other words, does endow humans with a variety of inborn traits, abilities and skills. But it is nurture, or the environment that takes the innate tendencies and molds them as we grow to adulthood and on. This does not end the nature vs nurture argument because scientists are currently embroiled in on going disputes about how much is nurture and how much is nature.

It’s well known that genes, one taken from each parent, determines traits like eye color or hair color or which hand is the dominant hand, left or right. These traits are encoded in every human cell in the body. Scientists who espouse the nature theory also say that abstract traits such as intelligence, aggression and sexual orientation fall under their purview, too. These traits, along with intelligence, for instance are naturally encoded in a person’s DNA. Scientists are on the hunt for the specific genes that may cause a person to commit crimes or lead to addiction. Perhaps the biggest modern day hunt is to find the gene that causes homosexuality. It is called the “gay gene.” Most scientists believe this “gay gene” exists because nearly all homosexuals maintain knowing their difference from birth.

Studies have been done, particularly on twins to test the hypothesis. For example, if genetics play no part in sexual orientation then fraternal twins, raised under the same conditions, we be alike, regardless of their genetic makeup. However the studies show the twin similarities manifest even when raised under different environments, tending to validate the nature theory.

However, scientists on the other side claim that only the environment matters when determining human traits and skills. Upbringing is the overriding factor, meaning that if your child is gay, you probably raised him that way. Many of these scientist maintain they can train or teach anyone to be anything they choose for them to be, totally discounting natural variations. More studies on twins, these identical show they are never exactly alike regardless of how they are raised, no matter what.

So, are people born the way they are? Or do they develop the way they are over time, shaped by their environmental experience? Experts on all sides do agree that nature vs nurture is not the same as cause and effect. To put it another way, just because a gene may increase the likelihood of a given behavior, it is never a case of the gene made me do it. So the bottom line remains that just because we may be genetically disposed to be one way, we still have the ability to choose how we are as we grow.


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