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Are people born gay?
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Identical twins can have different sexual orientations due to environment

Two identical twins that share the same genetics can have different sexual orientations. Identical twins don’t have the exact same mindset. Therefore, it’s environment that chooses sexuality.


Identical twin studies have been conducted to understand how the brain and body works. Identical twins share 100% of each other’s DNA, therefore, the physical studies are relatively easy. Mentally, twins share similarities and differences like any other sibling.

The Argument

Identical twins share 100% of their DNA. They have the same type of hair, skin, and blood type. Because they share the same DNA, twins are a great resource to find out how environment can affect individuals. In some studies, twins are asked to pick their favorite color, food, or even TV show. Scientists do this to see how far the twins’ identical characteristics go. Often, scientists are surprised to find that twins don’t always pick the same favorites. Environment has been proven to affect how each twin thinks individually. This also applies to sexuality. No two twins will have the same sexuality as the other. Sexuality is a choice. Choices are influenced by environment and strong feelings. The only way identical twins would have the same sexuality, is if they both chose the same sexuality.

Counter arguments

Identical twins should have the same sexual orientation. The gene Xq28 influences same sex attraction men.[1] It comes from the mother’s genes. But because there are lesbians, that means that there could be a gene from the father as well. Because of this, it proves that there’s a gene that does cause same sex attraction that would be inherited by identical twins. Identical twins share 100% of each other’s DNA. They would have the same sexual urges towards the same sex. If they don’t show signs of same sex attraction, they could be not truly identical twins, or they are suppressing their attraction. Another way that twins could not have attraction towards the same sex is if Xq28 was not activated. Since Xq28 isn’t found in every individual, it could be a genetic mutation. Mutations are not always activated in offspring. Therefore, having identical twins with different sexualities is not possible.



[P1] Identical twins share 100% of their DNA. [P2] Environment affects the growth and decision making of twins. [P3] Twins won’t have the same sexuality as each other because sexuality is a choice.

Rejecting the premises

[Rejecting P1] Not all identical twins share 100% of DNA. [Rejecting P2] Genes play an equal role of affecting identical twins’ growth and decision making. [Rejecting P3] Twins who share the same Xq28 gene activation should both be gay.


This page was last edited on Monday, 22 Jun 2020 at 18:59 UTC

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