The LGBT movement began when our first activists invented the concept of sexual orientation. Simply put, they needed the language and tools to identify, organize, and understand themselves. They needed new words so that they could advocate for the freedom of LGBT people to love and express themselves freely without interference from the government.

The concept of sexual orientation was invented by Karl Heinrich Ulrichs, a lawyer who made history in 1867 as the first person in the world to openly and publicly argue for the rights of LGBT people. Ulrichs believed that there was a biological basis to sexuality and gender nonconformity. He believed that the people we now call LGBT were "born that way", and that therefore discriminating against them was unjust. Over a century and a half later, this argument remains central to LGBT activism around the world. In his attempt to define and categorize human sexuality and gender, Ulrichs created a system of over 15 different terms.

His colleague, Karl-Maria Kertbeny, helped Ulrichs refine this concept into our modern framework of sexual orientation by simplifying Ulrich's dizzying array of terms into concise categories that broadly describe behavior. Kertbeny was not interested in what caused sexual orientation and even thought that arguing same-sex attraction was inborn could backfire. Instead, he focused on decriminalization and liberation, basing his arguments on the classical liberal idea that the government had no business regulating private, consensual sexual acts between adults. For Kertbeny, this was personal: when he was a young man, his close friend committed suicide after a blackmailer threatened to out him as gay. That loss stayed with Kertbeny, and he argued passionately that the criminalization of same-sex acts not only violated individual liberty, it also unjustly left people vulnerable to extortion.

In order to advocate along those lines, Kertbeny looked for language that would directly address the laws that left people so vulnerable. He focused on sexual behavior rather than identity because the government criminalized sexual acts, not people's sense of self or their inner desires. In a letter to Ulrichs dated May 6th, 1868, Kertbeny invented the terms homosexual and heterosexual.[1]

By creating language and a concept of people who experience a deep-seated drive towards same-sex intimacy, these pioneers made it possible for LGBT people to find one another. Now able to create community and come out of the shadows, they were better able to advocate for themselves legally and socially. This kicked off over a century of activism that, after eras of seemingly hopeless struggle and dire setbacks, finally resulted in the decriminalization of homosexuality, the legalization of same-sex marriage, and employment protections for LGBT people in many countries across the globe.

In 1892, Richard von Krafft-Ebing further built upon Kertbeny’s framework by coining the term “bisexual” for the 7th edition of Psychopathia Sexualis. He was a psychiatrist and sex researcher who wrote Psychopathia Sexualis for medical and legal professionals to better understand human sexuality. In writing his book, he discovered that no scientific terms were available to describe people who experienced both homosexual and heterosexual attractions, and so took it upon himself to create the word “bisexual”, meaning both kinds of attractions.

Although it may feel tempting to blame the idea of sexual orientation for the subsequent pathologizing of homosexuality and bisexuality, the reality is that at the time, most of the medical field viewed all non-procreative sexual acts as unhealthy. While this may seem hopelessly out-of-date today, it helps to remember that until the mid-1900s, most STIs were incurable and birth control methods were limited and ineffective. Religion also had a greater influence on the field of medicine than it does now. The realities of the day made it possible for people like John Harvey Kellogg (co-inventor of Corn Flakes), guided by his Seventh Day Adventist beliefs, to be instrumental in establishing circumcision as a routine medical procedure for male babies across the United States, supposedly in order to prevent the "evil" of masturbation. He even argued — successfully — that the surgery should be performed without anesthesia to clear the mind of ideas associating genitals with pleasure.[2] Fortunately, Kellog was unsuccessful with his companion recommendation that female babies should have their clitorises burned with acid soon after birth.

Despite this stifling atmosphere and the pioneering nature of their work, the activists who came up with the concept of sexual orientation and the scientific terminology to describe it were aware of gender diversity (including in non-Western cultures) and knew about differences in sexual development (intersex conditions). In an era when Origin of The Species was revolutionizing human thought, they were also keenly aware of the role evolution played in creating the two reproductive sexes through which our species continues its existence, as well as those sexes' role in fueling our drive to couple with each other. Gender identity was deliberately not included in the terminology of sexual orientation because gender is immeasurable, subjective, varies greatly across and within cultures, is fluid (i.e., subject to change), and more importantly, is not the axis along which sex acts and relationships are criminalized.

Bisexuality is a term that covers physical and romantic attractions to people both of the same and opposite sex. You may have come across claims that lump bisexuality in with issues of gender identity by suggesting that bi people either are or are not attracted to all genders. This is a misunderstanding of bisexuality, which refers to two types of attraction or behavior: both heterosexual and homosexual. It does not refer to gender identities, just as heterosexual and homosexual do not refer to attraction to or intimacy with specific gender identities. This is not to deny that such attractions exist, but merely to clarify that they fall beyond the scope of the term “bisexuality”.

In humans, there are four distinct sexual orientations: heterosexual, homosexual, bisexual, and asexual.

  • Homosexual: sexually-oriented to people of the same sex. "Homo" means same.
  • Heterosexual: sexually-oriented to people of different sex. "Hetero" means different.
  • Bisexual: sexually-oriented to people of both the same sex and different sex. "Bi" means two or both, in this case having two kinds of attraction.
  • Asexual: describes anyone who does not experience sexual attraction. "A" as a prefix means none.

The framework of sexual orientation invented by the pioneers of the LGBT movement continues to serve as a useful tool for advocating for our legal rights and dignity. As of 2023, same-sex marriage is legally performed and recognized (nationwide or in some parts) in the following countries: Andorra, Argentina, Australia, Austria, Belgium, Brazil, Canada, Chile, Colombia, Costa Rica, Cuba, Denmark, Ecuador, Estonia, Finland, France, Germany, Greece, Iceland, Ireland, Luxembourg, Malta, Mexico, the Netherlands, New Zealand, Norway, Portugal, Slovenia, South Africa, Spain, Sweden, Switzerland, Taiwan, the United Kingdom, the United States and Uruguay.

A multi ethnic couple holding hands against a green background.