I feel that I have to make absolutely clear that this whole trans-age and trans-species thing was something which I came across because of politically right-wing media, and most of it likens the purported ridiculousness believed-to-be nonsense of transness to the claimed ridiculousness of being trans-age or trans-species.
I by accident came across this concept of trans-age --- the idea that one really is another age internally on some level and or the idea that one wishes to be a different age, although one is biologically age X --- on YouTube and thereafter began to search it. In some ways it is strikingly familiar to transgender people's claims about having and or wanting to be/already being/always being from birth or perhaps even before birth, e.g. spiritually, a gender that is different from their sex, despite their having a sex which is typically either female or male, not intersex. Thus, I think it is interesting to ask whether or not one can be trans-age and whether, like the concept of transness is in my view, a valid concept?
Naturally there are some problems that arise when one asks such a question: if one is, for example, a woman of 60, yet one identifies as a girl of 10, does that not violate children's rights to protection and dignity, or at least endanger them, as that woman could potentially be with ill intentions with regard to the children, i.e. she could want to sexually or otherwise abuse them --- yes, I am fully aware how this criticism is very much like, even analogous to, the criticism of how trans people, but especially trans women, are allegedly "perverts" or more prone to perverse behaviour, or how they or cis people, especially cis men, who claim to be trans can gain access to toilets, changing rooms, etc., to live out their perverted fantasies and wants, so please do NOT think that these are the lines of support down which I am going, as I am in no way in support of such of you at all --- one thinks of this person, as this individual is the person to whom a lot of people go when they are thinking and or debating the alleged ridiculousness of transness and it's claimed similarities to being trans-age.
Likewise, if one can be trans-age, can one be trans-species, i.e. be human, but identify as a non-human animal, for example, e.g. like this individual --- yes, another right-wing thing on the Internet, but as I said all my sources are right-wing)?
Now, I do have to say that I have talked with some people who identify as otherkin --- people who don't identify as human --- and contrary to what is often touted by people, these people are not saying that they are not human biologically because they know that they are, just like a dyadic trans woman knows she is going to be understood as biologically male by most scientific standards, nor are these people ignorant of their being human on an objective level, by which I mean a level on which others will perceive them.
Interestingly, I did find [this] conversation on Reddit which addressed many questions that I had asked otherkin people, e.g. whether being otherkin could be understood as a mental illness or a departure from reality, etc., so definitely read through it.
Also, while searching on the Internet I came across this question on Reddit about whether transness and Gnosticism are related because, like being trans-age and trans-species, being transgender purportedly requires that one takes leave from reality by denying one's body, etc., as Gnosticism is believed to require one to do.
Though a layperson of anthropology and things so I may be fully wrong, it seems to be the case that in non-Western cultures there are social categories and things for people who are said to have spirits, souls, etc., of non-humans, e.g., and this seems to be accepted quite un-controversially.
Should social, legal categories for one to be a different age, species, etc., be crafted for people who feel this way?
Are trans-age and trans-species valid concept that should be embraced?
I have to also say that if gender identity is just subjective--- meaning that one is whatever one says one is, or whatever one feels oneself to be --- does that mean that one who doesn't feel human (like people who are otherkins don't) are not human in some way?