
He
presents Male-to-Eunuch as a "valid transgender identity" different from MTF in July 2007.
The supposed factors causing this "gender":
We identified four factors that may promote castration ideations: (i) abuse sustained during childhood, including parental threats of castration; (ii) homosexuality; (iii) exposure to animal castration during youth; and (iv) religious condemnation of sexuality.

"A Passion for Castration" - Aug
2007
Results:
The greatest reasons for those actively seeking castration were: reduction of libido (39%), sexual fantasy (36%), aesthetics (36%), 26% could not explain why, and MTF transition (20%).
Their conclusion: Physicians need to be aware of males who have strong desires for emasculation without a traditional MtF transsexual identity.

He wrote a draft Standards of Care for "Male-to-Eunuch Gender Identity Disorder" in 2010. This is
paywalled and only an abstract is available. Of course, it's conducted through a survey on his favorite website for fetish fiction. The urgent need for "gender affirming" castration of eunuchs is because about
150 total men report they went to an underground surgeon or performed the castration themselves.
An online survey posted at
www.eunuch.org provided data on more than 300 individuals who have had voluntary genital ablations (as well as approximately 1,300 self-identified "eunuch wannabes"). More than half of the men who had surgery either did it themselves or resorted to medically unqualified underground "cutters." This article offers a draft MtE SOC that outlines the criteria that we believe should be satisfied prior to surgical treatment.

"Religiosity, Childhood Abuse, and Other Risk Factors Correlated With Voluntary Genital Ablation"
2013 -- His research finds over and over again that the population seeking castration is full of those with trauma and abuse histories, including sexual abuse, their parents threatening to castrate them, as well as their parents being very religious, and them being homosexual or bisexual.

"Castration and Personality"
2013 -- While in his WPATH presentation he reports that those seeking castration hope to achieve a personality change, and that castration will achieve this,
his own research found no evidence for this claim.
Based on the historical social positions of androgen-deprived males and contemporary research on testosterone, we predicted that modern day androgen-deprived males (n = 122) would differ on several axes of the Big Five factor personality inventory compared to eugonadal controls (n = 1229). Though not statistically significant, an increase in agreeability for the androgen-deprived group was observed. The role of estrogen on the personality of castrated males was also explored through androgen-deprived participants taking supplemental estrogen (n = 33). Estrogen was found to correlate with significantly higher agreeability scores.

"The hidden world of self-castration and testicular self-injury"
2014 -- This is a paper he worked on with Michael Irweg, the urologist who also is involved with the SOC, it's about the 2nd patient he references.
2014 study about the people performing underground surgeries again illustrates the high rates of abuse and childhood issues. No mention of gender dysphoria type symptoms.
Results. Distinguishing characteristics of cutters [who perform amateur castrations] included: (i) presenting themselves as very masculine, (i) having had their longest sexual relationship with a man, (iii) growing up on a farm, (iv) witnessing animal castrations, (v) having a history of sexually inappropriate behavior, (vi) having been threatened with genital mutilation as a child, (vii) having a history of self-harm, (viii) being raised in a devoutly Christian household, (ix) having had an underground castration themselves
2015 -- He just loves to write about his favorite website. He's finally done enough groundwork that now he can pass off reading fetish stories about minors as research!
Common themes in both stories and personal histories of voluntarily castrated men were homosexuality, childhood abuse, and threats of castration. We found that 83% of stories were explicitly sexual, which was defined as containing physical or mental sexual arousal; sexual acts such as masturbation, oral sex, or penetrative sex; or attainment of orgasm. Fifty-one percent of stories described forced castrations, 34% involved minors, and 24% described orgasms related to genital ablation.

And
another one! He argues that his favorite castration erotica site is valuable in order to understand gender identity.
2019 -- Now he analyzes eunuch fetish stories "in the context of well-established models for human sexual response".

Here is a bizarre article published in 2021 where he is providing consultation to a father whose child was castrated for a medical issue. They encourage the father to seek advise from an endocrinologist, then they contradict the endocrinologist: "In contrast, the literature suggests that puberty can be safely delayed at least until the boy is the age of majority."
In
2022 he published yet another paper about Eunuch Archive stories. This one again highlights the prevalence of minors in these fetish stories:
The most popular EA stories link sexual gratification and romantic partnership with genital abuse. They are characterized by the absence of consent for genital ablations and multiple SM-related paraphilias. Many stories feature attraction to, and ablation of, the genitals of pubescent or adolescent males.
... This is the article published right before the SOC comes out adding eunuchs. LOL!

The
article he published directly after SOC 8 also concludes that attraction to castrated men is most associated with childhood trauma, body image, and being attracted to being castrated themselves.

His most recent
article reports "Most (46.3%) wished to achieve an idealized self motivated by gender dysphoria, body integrity dysphoria, or wanting to be conspicuously non-sexual." In the study, they make 0 distinction between "gender dysphoria" and wanting to be non-sexual. It's completely unclear how many respondents referred to gender identity, in fact when you look at the responses featured in the article for the 1 question which relates to this conclusion, you would predict that likely a minority of the open-ended responses would be coded as experiencing gender dysphoria.

He often publishes with another eunuch-obsessed publisher,
Richard Wassersug.