Sexual orientation is the continuous romantic and sexual attraction to other individuals. Children often develop these relationships choices as they age. Once they become adults, society likes to categorize these different sexual orientations. As these varieties are becoming more accepted by the majority, people often question if these different sexual preferences are caused by the environment of a growing child or decided at birth. As humanity advances in pre-birth and biological studies, we have found that yes, indeed, sexual orientation is determined at birth. Researchers have established many environmental influences that are involved as early as the pregnant process. Scientists led by Dr. Dulac from Harvard University have conducted studies that show when babies are exposed to a certain higher level of the serotonin hormone while in the mother’s womb, they are prone to becoming “queer”. In fact, they exposed female mice to high levels of this hormone and resulted in these mice trying to conduct sexual behavior with the same sex (Hamblin). Another study had found that sexual orientation may be directly related to another hormone, progesterone. Progesterone is a hormone prescribed by doctors to pregnant mothers -in the means of stabilizing the menstrual cycle and to prevent miscarriages. This study looked at 34 people (17 males and 17 females) whose moms took progesterone while pregnant. The participants were asked to fill out a survey and participate in a formal interview with a psychologist, who asked them questions relating to their sexual orientations and histories. The results of this study concluded that these individuals were 24 percent more likely to have ever had any sort of same-sex sexual behavior, 29 percent more likely to be attracted to the same sex and 17.6 percent more likely to be attracted to both sexes (Jalili). The human body is a complicated system that humanity has not yet fully understood. As studies further progress into the complications during child development in the womb, we discover the many hormonal influences that come into play. A child is vulnerable in the womb and has no ability to choose or deflect the hormones they are exposed to. These natural occurrences inside the womb are able to alter the sexual orientation of a child before they are born and to an extent are able to be manipulated by drugs and medications. These studies further imply that one’s sexual nature is pre-decided, even before they are born. As studies have found, there are also many physical differences between “queer” individuals different from others. D.F. Swaab conducted the first experiment to document a physiological difference in the anatomical structure of a homosexual man’s brain. Swaab found in his post-mortem examination of homosexual males, a small portion of the hypothalamus, termed the suprachiasmatic nucleus (SCN), was found to be twice the size of its heterosexual counterpart. (TheAtlantic) More importantly, the hypothalamus is the portion of the human brain directly related to sexual drive and function. In 2010 a Meta-analysis study by researchers from the University of Ontario, Penn State, and the Centre for Addiction and Mental Health found that the second to fourth finger length ratio (2D:4D) serves as an indicator of sexual orientation. The study included 1 618 heterosexual men, 1 693 heterosexual women, 1 503 gay men, and 1 014 lesbians. They discovered that the finger length of “queer” men was closer to the measurements to the ones of heterosexual females and vice versa for “queer” females. In the same study, 5,000 men gave measurements of their erect organs. The study concluded that the gay men’s penises were thicker (4.95 inches versus 4.80) and longer (6.32 inches versus 5.99) (WordPress).These physical differences between “queer” and heterosexual adults help us foresee altered sexual orientations through the biology of an individual. These differences cannot be decided, they are rather naturally developed. These obvious physical variations implement that the sexual nature is not decided and at the same time becomes more evident as one develops. Some may say that if a child experiences trauma or abuse, this may be a leading factor to having a differentiated sexual orientation. This is the result of individuals believing that having a different sexual nature is due to a mental disorder or the inability to cope with emotions. However medical experts and organizations such as the American Academy of Pediatrics (AAP) and the American Psychological Association (APA) view sexual orientation as part of someone’s nature, ruling out being “queer” as a psychopathic problem(Kidshealth), further inferring that being gay is also not considered an abnormality. Throughout their childhood, children often express their sexual preferences without even understanding the meanings of sexual orientations. Individuals are not able to control what category of sexual orientation they belong in, often they feel it is by nature. In fact, there are many determining factors when we are still in our mother’s wombs. As we grow up, we also see many biological differences between individuals who classify in different sexual orientation groups. Neither of these scientifically proven variations can be decided. Sexual orientation is a concept formed by nature and there is absolutely no choice involved at all. Sexual orientation is determined at birth, meaning that individuals possess differentiated hormone levels and body parts since the moment they are born.