"The twenty-first century has seen wider acknowledgment of the fact that human sexuality is much more complex than the rigid and unchanging categories of heterosexual, homosexual or bisexual can express; the experiences of trans people are just one part of this increased sexual diversity. In the case of non-binary people – whose gender identities and expressions may sit outside of the categories of man and woman, or move between the two – the nineteenth-century categories of human sexuality make little sense – which is why the term ‘queer’ has risen in popularity."