No, homosexuality is not genetic. But neither do people choose to have homosexual feelings.

Genetics is the domain of science. So let’s consider what science has found regarding homosexuality and genetics. First, science has found that sexuality and sexual orientation are some of the most complex aspects of people and the answers to simple questions like “Is homosexuality genetic?” are not simple. For example, science does not have any test that can identify homosexuals from heterosexuals – no gene or DNA test, no blood or hormone test, no organ test.

Some people have studied twins. If homosexuality is solely genetic, you would expect to find a one-to-one correlation of sexual orientation for identical twins. In other words, every time one twin was homosexual, the other identical twin would be too because they share identical genes. Twin studies do not show this. The study by Bailey and Pillard, published in 1991, is often reported as a major study of twins. They did not find that all identical twins are always both homosexual. They did find that when one twin is homosexual, the number of times the other twin is also homosexual occurs more often than the general rates of homosexuality in society. The media reports this is proof that homosexuality is genetic. But the researches themselves clearly stated that this study did not prove that homosexuality was solely caused by something genetic. Interestingly, this study also looked at the rest of the family and they found that the rates of homosexuality among the rest of the family, including adopted brothers was 200-300% more frequent than the general rates in society. And so the data leads to the conclusion that something is causing homosexuality to occur more frequently in certain families but that it can not be genetics because the increase even occurs in adopted brothers who do not share any genes at all with the rest of the family.

When all of the work being done to understand causes is put together, the question about what causes homosexuality seems best answered as follows. First, science does not have a firm answer that everyone in the field of science let alone everyone else can agree on. The origins of homosexuality are still not clearly understood by scientists and the topic is the subject of debate. The scientific evidence about its cause or causes is inconclusive at this time. Second, science can say that the search for causes is better understood as a combination of causes rather than a single cause. It may be more accurate and more helpful to consider that a combination of psychological, environmental and biological factors together with human choice contribute in ways that vary from person to person to cause homosexuality.

It is also important to note that each individual who experiences same-sex attraction or later identifies as gay or lesbian will have unique predispositions and experiences that contribute more or less to that person’s emerging sexual identity. In other words, these predispositions and experiences are weighted differently for each individual.

Another comment is needed about the nature of human choice. We just said that psychological, environmental & biological factors combine with human choice in ways that vary from person to person to cause homosexuality. Human choice can be accurately viewed as one of the factors influencing the development of sexual orientation but this is not meant to imply that people consciously decide their sexual orientation. No one decides on a specific day that from that day onward that they will be a homosexual. Instead, sexual orientation is shaped and reshaped by a series of many choices and response to circumstances in one’s life and enormous social and cultural pressures.

In conclusion, we are not saying that there are no biological factors involved in homosexuality. We are not saying that psychological theories have been proven and are the only factors. And we are clearly saying that people do not choose to have homosexual attractions. The question of what causes homosexuality appears to have a rather complicated answer. The scientific evidence about its cause or causes is inconclusive at this time. But what is clear is that we do not have to adopt an either/or approach when looking for what causes homosexuality. The search for causes is better understood as a multi-faceted combination of causes.

For more information about the roots and causes of homosexaulity, please go to the Articles section.

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