 I'll admit, I never understood the attitude so many people had to non-binary genders. That is, until someone sent me a link to a Tumblr about gender identity, and I realized the internet's taken something a little outside our experiences, and magnified it to a bizarre degree that I no longer recognized. So lesson learned, there clearly are limits to what can be rationally defended with regards to gender identity. But I think it's worth drawing a line between what is and isn't clear about sex, sexuality, and gender. It's a far more complex topic than most people realize. First, sex. This is the characteristic defining our reproductive status. If you think outside of the mammalian world, where we have almost exclusively male and female, sex just means distinctive subtypes that could potentially exchange genetic information. Some species of yeast can have seven mating sexes. Each of these sexes can exchange genetic material with the other six, but not with members of the same sex. Most plants are hermaphroditic, with male and female sexes on the same plant. So are many slugs and snails and even a few fish species. In fact, about 5% of all animal species are hermaphroditic. Some fish change sex during their life cycle. These are sometimes called sequential hermaphrodites, going from male to female, or vice versa depending on living conditions. Humans, like most mammals, are mostly male and female by genitalia. But there are rare individuals that we term intersex. These are people with genital ambiguity. They might have functioning ovaries and testes, or one organ with both functions. They might have outer genitalia, including penis and vagina or vulva. This is rare, perhaps one in 80,000 births. But it's a continuum with non-functioning diminished organs, all the way to fully fertile gonads of one type or the other. Second, we have the other way to define sex, our genetic sex. Females in mammals have two X chromosomes, while males have one X and one Y chromosome. Outside of mammals, sex chromosomes are far more diverse, a topic I won't even go into. In humans, besides the standard X, X, and XY, there are also people who have only a single X, no Y, no X to go with it. We term this XO, or 45X, and the condition it produces is called Turner syndrome. Turner's patients are considered female but are infertile, never have periods and don't develop breasts or produce estrogen. They lead otherwise normal lives, have normal intelligence, and many are on estrogen supplement therapy so that they can live their lives as females. As many as one in 2000 life births are XO. People with two X chromosomes and also a Y chromosome are called XXY, and the associated condition is called Kleinfelter syndrome. These individuals typically live as males. They are sterile, have smaller genitals, grow female type breasts, and have lower sex drive. They also have normal intelligence and lead normal lives, but many choose to take testosterone to reduce female sex characteristics and enhance maleness. Up to 1 in 500 life births are XXY. There are many other combinations of the two sex chromosomes, for example XYY, who are male, fertile, and in fact often don't know they have a sex chromosome abnormality, or XXX, which is the exact equivalent in females, rarely diagnosed and with very little impact on their phenotype. All of these occur at a rate of around one in a thousand life births, which to my mind is somewhere between rare and common. At the much more rare level, there are even people who are a mixture of male and female at the cellular level. If we added together all these exceptions, all these categories of non-binary sex, as defined by genetics in genitalia, I think it would be something like one in 400 life births. All of this is simply to establish how much more complex biological sex really is relative to what we're probably used to. These are not trivial issues, but because the prevalence rates are relatively low, and because sex is a taboo subject, you may not be aware of how common non-binary sexes are. When it comes to gender, we have a different concept to deal with. Gender is cultural. It's how we perceive and treat people. Certainly it's rooted in biological sex, specifically through secondary sex characteristics like the shape of hips, waist, breasts, hair on the face or chest, but it's also very cultural. Men behave a certain way, dress a certain way, while women have their own norms of dress, behavior, and appearance. Our stories throughout history tell of men who passed for women and women who passed for men. In modern cultures of the west, we've mostly settled on the two genders that correspond to the two most common sexes. Adult males are men, and adult females are women, but that hasn't always been the norm in all cultures. A classical case is found among Native American tribes. French explorers in the 17th and 18th century found that the plain tribes almost universally had a third gender, which they called at the time of Burdash, renamed to Two-Spirit in recent years. This was almost always a male who at some point in their young life had a dream or vision that led them down a different path, including combining clothes and duties of both men and women, as well as having special religious significance and responsibilities, like being the go-betweens and arranging marriages, making love potions or spells or blessing weapons or warriors. Similar examples are found in Asia where the hijra gender is legally recognized by the governments of India, Pakistan and Bangladesh. The hijra have no perfect correlation with Western ideas of man and woman. They are generally physically male, dress as women, but are treated as a distinct third gender. Relationships between a hijra and a man are not considered homosexual, and these relationships can end in a legal union that is not seen as same-sex marriage. If we go further back in history, we find that the ancient Egyptians had three genders, male, female, and sequet. The Inca had a third gender with special religious significance, as did the early Indic cultures, the Babylonians, the ancient Greeks. What we consider normal or proper is the result of the world we grew up in, and it changes over time. So, no, I don't think gender identifying as an attack helicopter or as fishkin is normal in the sense of part of our cultural norms. I don't think the strong converse can also be supported. Not everyone will fall into one of the two sexes or two genders. Our history, feelings, and biology are occasionally more complex than your upbringing has prepared you for. If I can suggest one thing about this topic, if it doesn't directly affect you, let it go. The people who are wrestling with difficulties in finding their sexual and gender identities will not be much helped by either your scorn or your indulgence. If it is an issue you're dealing with, I highly recommend, as I always do, that you talk to someone in a position to help you. A doctor or a counselor would be ideal. Take care of yourself, whatever your sexuality, sex, or gender, and my best wishes for your good health. Thanks for watching.