Susan's Place provides a list of definitions and terms, including these:
Crossdresser: a person wears the clothing of the opposite gender, and has no desire to permanently change their sex. There is generally no sexual motivation for the cross-dressing.
Transvestite: a person who wears the clothing of the opposite gender, and has no desire to permanently change their sex. There is generally a strong sexual motivation for the cross-dressing.
I would contend the two terms are artificial and should be combined into one, because their major features are a liking for wearing the clothes of another sex and perhaps to pass as a member of that sex.
Not wishing to have sexual reassignment surgery (SRS) is a separate and complex strand, but some people who crossdress will eventually opt for surgery and some will never get as far as considering it.
This is important, because some people who like wearing clothes designed for another sex have come to terms – for all kinds of practical reasons – with not going down the SRS route, but still allow themselves the dream of being another sex, even if they have decided to stay with the one they were assigned at birth.
The motivation for wearing clothes associated with another sex has complex roots. People have crossdressed for millennia, but the practice only came to prominence when psychiatrists got involved. That began with the publication of Carl Westphal's Die Conträre Sexualempfindung or The Contrary Sexual Feeling, in 1870, which led to the medicalisation of gender expression.
The word transvestism is even more recent, dating to 1910. It was coined by the sexual scientist and gay rights activist Magnus Hirschfeld. The full title of his book was Die Transvestiten: Eine Untersuchung über den Erotischen Verkleidungstrieb or Transvestites: The Erotic Drive to Cross-Dress and it was ladled straight into the simmering soup of the emerging specialty of psychoanalysis. In those days, cutting edge thinking held that everything that wasn't normal might have its roots in sexuality. Somewhere. However unlikely the connection might be.
With due respect to my own profession, if you are a hammer, everything looks like a nail. This is an area in which there has been little research and such studies as there are frequently rely on small numbers, are anecdotal, or are motivated by such a strong bias as to hardly qualify as research at all.
If you take the view that non-standard behaviours are pathological and that gender and sex are the same thing, then I guess the motivation for dressing up in the clothes of another sex must be explained by some sexual reason. Preferably buried deep in your past and only accessible through the skills of an analyst.
Against this, even the UK's recent Cass review of gender identity services for children and young people draws a line between gender and sex. In the report, the committee used the Office for National Statistics' (ONS) definitions:
Sex: "referring to the biological aspects of an individual as determined by their anatomy, which is produced by their chromosomes, hormones and their interactions; generally male or female; something that is assigned at birth".
And...
Gender: "a social construction relating to behaviours and attributes based on labels of masculinity and femininity; gender identity is a personal, internal perception of oneself and so the gender category someone identifies with may not match the sex they were assigned at birth".
We aren't naturally gendered when we are born – it comes to us later through a diverse and mostly subconscious learning process, or as Simone de Beauvoir memorably put it, 'One is not born, but rather becomes, a woman'. She could easily have written, 'One is not born a man, but rather learns to become a man,' but that would have played merry hell with the title of her book.
As the ONS definitions of gender and sex are at pains to point out, since one is not necessarily congruent with the other, it is hardly surprising that some of us end up in a situation where the two do not march in lockstep. Do notice that the ONS makes no mention of sexuality at all in its definitions, because being assigned a particular sex at birth does not necessarily mean that you will be attracted to another sex or that you will be gender conforming with your own sex.
From which drops the realisation that you can grow up to be non-gender conforming and like wearing clothes belonging to another sex without any sexual motivation for doing so whatsoever. Or grow up every shade between there and having a strong motivation for doing so, because that's the way the human race works – we aren't binary and almost every one of our characteristics, physical or mental, is a point on a spectrum.
This is what makes people so much fun, our differences, not our similarities.
Which takes me neatly to my final point. My partner and I have a friend who describes herself to all and sundry as a butch lesbian. Yet most people don't realise she is one because lots of women dress like men, right down to short haircuts and work boots. At times it has been the peak of fashion and through familiarity we accept it to the point we are no longer aware of it, though society did not accept women crossdressing in 1910, back when Hirschfeld published.
Today, we are so used to women dressing with male gender expression that few would call it crossdressing or transvestism, but more to the point, I have never heard anyone suggest that women who like dressing that way do so for sexual gratification. Although, based on my understanding of human variability, I am sure some do.
Yet for men with female gender expression, the rules have changed little since Hirschfeld's time. To be sure, the American Psychiatric Association's (APA's) DSM-5-TR classification very generously does not classify a man who, 'likes to dress in women's clothes but does not identify as a woman and otherwise lives typically as a male' as having a psychiatric disorder. That's progress, kind of.
The key point here is that DSM-5-TR mostly calls such a desire transvestitism, but uses the word cross-dressing as a synonym. This is the APA speaking – one of the most conservative (small c) medical associations in this arm of the galaxy.
The DSM-5-TR also has a diagnosis of 'transvestic disorder' but makes it clear it "does not apply to all individuals who dress as the opposite sex, even those who do so habitually." Instead, the DSM only considers transvestism a disorder if "cross-dressing or thoughts of cross-dressing are always or often accompanied by sexual excitement."
Waiting for the DSM to change is like watching an oceanic iceberg melt. To afficionados of the DSM like myself, the runes are clear and transvestic disorder is headed for the scrap heap, soon – which in the APA's terms means it could be as imminent as late this century. Yet even the APA conceptualises crossdressing and transvestism as the same thing, even while its DSM presents one as a disorder and the other as part of what we call normality.
Perhaps we should do the same and merge the two terms? Only we could beat the APA to the draw by a decade or two by dropping the sexual motivation thing?
If you have any views, please contribute!