The debate of nature vs. nurture is one of the most widely argued subjects of modern psychology. People who believe that nature is stronger in personality development think that everything, or nearly everything, is determined by one's genes before birth. Those who agree more with the nurture side think that we learn to hate, like, or tolerate things. The most realistic explanation is that half of one's development is nature-based, and half comes from nurture.
The nature side of the argument states that people behave according to their genetic predispositions. Eye color, hair color, height etc. are all determined by genes. Scientists are now saying that personality, aggression, and even intelligence are partly determined by DNA. Some even say that there are behavioral genes that are yet to be discovered. If these genes were confirmed, then genes could be blamed for criminal acts or justify addictions. The most widely argued aspect of the nature explanation is homosexuality. Some believe we are only years away from discovering the "gay gene". If there is a "gay gene", then there must be a "straight gene" as well, right? In time we may know the answer to this and many other questions.
Twin studies have given vital information to the Nature/Nurture debate. In these studies, sets of twins who were adopted to different families, many in different cities and states, were analyzed to see if they exhibited similar behavioral traits over their lifetime. Many cases supported the Nature idea, with twins living hundreds of miles apart, never meeting one another, and yet having similar preferences for food, clothing, entertainment, and even similar speech patterns and/or impediments.
On the other hand, why do some identical twins have completely different tastes and styles? Genes must not be the only determining factor in one's personality.
On the other side of the argument is the nurture theory, which states that personality, likes, dislikes etc. are determined strictly by the way one is raised. Although Nurture supporters favor a largely nurture theory, they don't completely rule out genetic predisposition. After all, you can't become blue-eyed because your mother raised you to like the color blue. For example, Howard Hughes was raised by parents who were extremely afraid of contracting bacterial diseases. Subsequently, Hughes became a major Germophobe with an extreme case of OCD. Who can say whether this was imprinted in his genes from his Germophobe parents, or if he was taught to fear unseemliness.
While most people agree with the nurture aspect, the most effective explanation blends these theories together. Shorter-than-average people tend to have a certain personality, which is somewhat genetic, but there are also social skills that these people develop during childhood, just like a normal-sized or tall person develops. With no definite explanation, the debate will continue for many years to come.