Changes in the sexual orientation of six heterosexual male-to-female transsexuals.
Daskalos CT.

Abstract
Researchers traditionally have assumed that sex reassignment procedures do not change sexual orientation. Of 20 transsexuals of various types that were interviewed, 6 heterosexual male-to-female transsexual respondents reported that their sexual orientation had changed since transitioning from male to female. These respondents stated that before transitioning they had been sexually orientated towards females. After transitioning, these same respondents reported that they were sexually orientated towards males. Five of the six respondents reported having various sexual encounters with males since transitioning. The respondents explained the changes in their sexual orientation as part of their emerging female gender identities. Three of the respondents claimed that the use of female hormones played a role in changing their sexual orientation. It did not appear that the respondents' post-transitional sexual attractions towards males were similar to autogynephilic images and fantasies described by Blanchard (1991).

http://www.ncbi.nlm.nih.gov/pubmed/9883308

n=6 in this 1998 study.

Now there must be more people who are taking HRT. Is there any study done on a larger size of sample?

I've wondered about this, the physical vs the emotional aspects of reorientation. Anecdotally, I had heard many cases of a change, and had been told when I started to transition that outcome regarding orientation really was anyone's guess.  There is research revealing that estrogen influences how female brains repair and rewire more easily than male, and we know that on HRT over a period of time every cell is more or less "reprogrammed."  I've wondered whether the repair also sparks a slow reworking, and whether it accelerated or magnified any tendency over time.  Attraction is so emotional as well, and I wondered if people "let loose" on HRT and especially post transition, and that they become less inhibited to explore an attraction. I also wondered whether the research on brain differences done postmortem and showing correlation of female brains and MTF transsexual brains was performed on women who had long been on HRT, and whether that treatment had any influence. This research suggests some impact on the orientation alone, which even without HRT isn't well understood, but as Hans asks, is there a study for a larger sample?

A survey of 20 people is not statistically significant, so you can't really take much of anything from a study like this except maybe for some indication that could indicate the need for a larger study. But yeah, it doesn't even mention if it controls for cases where the attraction was there already before HRT and the subjects hadn't felt comfortable pursuing it before transitioning.

  This is an old study.  More data is needed.  ->-bleeped-<- along with my type of neuropathy is mainly on anecdotal data.  There seems to be a higher percentage of those changing their sexual orientation after being on HRT and having the surgeries after 2 years on this forum group alone.  However, these people are on a forum group that are revealing their feelings and not those whom do not do so at all and transition in stealth.

  Joelene

I almost ignore any research that is < n=100, PERIOD. I also look at various other aspects of their research such as, has it been repeated and verified by other researchers? What was the sampling method used? If it was a survey there is a host of other variables that can skew the results and make it unreliable and invalid such as not allowing for uncertainty, response categorizes are not exhaustive nor are they mutually exclusive and other things such as not allowing for disagreement. That said, I don't believe sexual orientation "changes" what I do think is that people (and society) are simply more comfortable in what used to be considered homosexuality. A person's sexual orientation does not change, however, their preferences do. We live in a society that has long been known for harsh treatment of anything that is aberrant to established norms and ideologies and many people suppress their orientation lying to themselves that they are, in fact, heterosexuals. When they transition a bit of dissonance transpires because now they find themselves homosexuals (e.g. A previously male person now female still is attracted to women). It's not as easy to deal with as many people think. It's also hard for them to rationalize liking men because many transsexual woman have not come to grips with who they are and the fear of further stigmatization influences their behaviors because of how society still views the transsexual woman as a man thus, them being in a relationship with a man would be a homosexual relationship. Sort of a paradox...

My therapist wrote a book on the subject: "When The Opposite Sex Isn't: Sexual Orientation In Male-to-Female Transgender People"

In her study of 97 MtoF people, about 5 or 10 (I don't remember the exact number from the book) changed during transition from being attracted to females to being attracted to males.  None moved in the opposite direction. The change didn't seem to correlate to HRT.

Kim 

Quote from: KimSails on July 25, 2014, 02:54:24 PM
My therapist wrote a book on the subject: "When The Opposite Sex Isn't: Sexual Orientation In Male-to-Female Transgender People"

In her study of 97 MtoF people, about 5 or 10 (I don't remember the exact number from the book) changed during transition from being attracted to females to being attracted to males.  None moved in the opposite direction. The change didn't seem to correlate to HRT.

Kim 

I wouldn't say none I was completely into males pre transition and since I've transitioned I've mainly been dating women. Still attracted to males though ah the perks of being bi.