The Scientific Realities of Biological Sex || Debra Soh, Marco Del Giudice, & Buck Angel

March 16, 2023

Today we welcome Debra Soh, Marco Del Giudice, and Buck Angel.

Dr. Debra Soh is a neuroscientist who specializes in gender, sex, and sexual orientation. She holds a PhD in neuroscience with scientific expertise in paraphilias, hypersexuality, and child sexual abuse prevention. As a journalist, her writing has appeared in several publications like the New York Post, the Wall Street Journal, and many more. In 2020, she published her first book called “The End of Gender”.

Dr. Marco Del Giudice is an associate professor in the Department of Psychology at the University of New Mexico, Albuquerque. He received his bachelors in psychology and doctorate in cognitive science from the University of Turin in Italy. He has over a hundred scientific publications on personality, motivation, attachment styles, psychopathology, sex differences, and other topics. In 2016 he was granted the Early Career Award of the Human Behavior and Evolution Society (HBES).

Buck Angel is an adult-film producer, performer and motivational speaker who also works as an advocate, educator, lecturer and writer. He has served on the Board of Directors of the Woodhull Sexual Freedom Alliance from 2010 to 2016. Born as a biological female, Buck conquered a lifetime of adversity to undergo his transformation to become the healthy, happy, self-confident man that he is today. Buck created the first FTM adult website in 2003, and became the first FTM adult entertainer and film producer. In 2007, Buck made history again as the first transexual man to ever win the AVN transexual performer of the year award. 

In this episode, I talk to Debra, Marco, and Buck about the scientific realities of biological sex. There is considerable opposition against the idea that sex is binary. But denying science because it doesn’t seem to fit our gender beliefs can be dangerous. As ironic as it seems, when we acknowledge biology, we can accommodate more variation better than our preconceived, rigid social norms.

Website: drdebrasoh.com , marcodg.net , buckangel.com

Twitter: @DrDebraSoh & @BuckAngel


  • Dr. Marco’s background and expertise 
  • Dr. Debra’s background and expertise
  • Buck’s background and expertise
  • Shift from ‘transexual’ to ‘transgender’ 
  • The separation of sex and gender
  • Why feminists reject biology
  • “It is transphobic to deny biology”
  • Extreme trans activism 
  • Transgenders vs TERFs
  • Being gender fluid is trendy
  • Losing the nuances in gender
  • The evolutionary perspective of traits
  • Dismantling the definition of woman
  • De-transitioning and safe healthcare
  • The construction of gender identity
  • Social transitioning through pronouns
  • Non-binary and non-specific labels
  • Prioritizing truth over feelings

14 Responses to “The Scientific Realities of Biological Sex || Debra Soh, Marco Del Giudice, & Buck Angel”

  1. Charlie says:

    Buck did a lot of “they want this” and “they all lie” but very little cogent analysis. His view is as useful as any other man-on-the-street’s, which is to say, not much. If he knows about a doctor in Florida who does top surgery on children after a 20 minute discussion, he should first report them to the AMA, and second, stop using that doctor as an excuse to imply any child can get any gender surgery at the drop of a hat. Which is, what’s that word? – oh yeah- a LIE!
    You can tell when a scientist is talking about something factual because they don’t rely on emotions. Debra may technically be a “scientist,” but she was not speaking scientifically in this podcast. Instead she was trying to use science to back up her emotional realities (like Trump talking about Covid).
    Neither guest was worthy of your podcast, which was nowhere near your usual standards.

    • Matt says:

      Looks like you have just discovered that well rounded arguments contain elements of ethos and pathos. If you want more logos see the conversation with Carole Hooven.

    • Marc says:


      You claim that Angel is lying only because you aren’t aware of stories like why the Tavistock gender clinic in the UK was shut down, or you haven’t heard of whistleblower Jamie Reed’s ongoing revelations about shoddy gender clinic practices in Missouri.

      If you’d just read up on these as well as interviews with detransitioners you’d realize the clinical standards for recommending transitioning have fallen greatly since Angel’s time, and now it is almost too easy for a child to be prescribed puberty blockers and hormone treatments even when their issues have not yet been thoroughly assessed as stemming from distress due to gender dysphoria and not other psychological problems.

  2. Yu Pa says:

    The guests backlash those who identify as non-binary and each of the guests back each other up and are supportive of each other on the stance. There was no diversity in the guest, rather it appeared as a gang coming together in defense of making light of those who identify as non-binary. It was hurtful and hateful. The tone of Black Angel was harsh. He sounded angry and he is not an expert. He can only talk about himself when he states that being trans is a mental disorder. He should not make a blanketed statement that trans is a mental disorder. It is not.

    The sort of engagement is not one of open listening of alternative perspectives, but one of a false absolute truth or reality of gender.

    Unlike what Debrah Soh had stated, changing definition of things is NOT denial, it’s evolution of thought.

    There was no open engagement and the willingness of the guests to be open to other perspectives. Also the guests selection was poor. They all affirmed each others position. It felt gang-like.

  3. Karen says:

    Thank you very much for putting this panel together. Scientific findings must be based on data, not political or ideological agendas. Politics and ideology have no place in science, yet all too often, regrettably, they pervade public debates on topics relating to science. Science must not kowtow to anyone’s personal feelings or to perspectives that are not based on verifiable data.

  4. Michal says:

    The series is really interesting. Thanks, Scott!

    I don’t think each episode within the series needs to be balanced. The series as a whole ought to be, and seems to be.

    I found some of Dr Soh’s statements a bit jarring. But she’s a neuroscientist rather than a psychologist. haha Anyway, throughout its relatively brief history, when compared to existence of our species, science has gotten many things right and brought about huge advances, but has also repeatedly interpreted the data of the day in ways that we now consider incorrect if not absurd. At times, it was used to promote freedom, at other times, oppression. Without denying that there is such a thing as subjective and objective, it behooves us to treat the word “objective” with caution and circumspection; not realizing that what you’re looking for influences what you see, is hubris… or fundamentalism. Outcries about “denying the science” might come from the same place as the denials of science, might they not? Also, definitions are clearly not intrinsic and immutable properties of objective phenomena. Fortunately. They change as humanity evolves. Case in point: the definition of marriage has changed several times already.

    I agree with Matt regarding the conversation with Carole Hooven.

    Anyway, keep up the good work, Scott!

  5. Matt says:

    Yeah michal, I think “objectivity” is at the core of this argument. Objectivity as a concept is a paradox because it only exists when we are looking through the same framework or from the same perspective. Objectivity defined as absolute truth is an ideology or a fiction because we do not have access to absolute truth and like you say, to pretend we have access to it is hubris.

    So from the perspective of sports it’s objectively true that trans women have an advantage over cis. From most other perspectives however it’s objectively true that transgender people are just like everyone else and should be left in peace.

    • Matt says:

      Can’t edit so I’ll reply.

      Much of the consternation surrounding this topic is due to the fact that activists are loud and control the conversation. An “Activist” can often be defined as a perspective totalitarian and no one can stand it when they are told what their perspective is or should be.

  6. Katerina says:

    I am a big fan of this podcast, it’s really well done bringing in great topics. I was excited about the theme of the series and I have high hopes for it considering the generally very high quality of the podcast. As a scientist (STEM), I enjoy how rigorous the discussions usually are. I was a little disappointed by this episode however. While it mentioned some interesting points, which made me think about new aspects of gender identity, I felt it was quite unbalanced and rather lighter on the science. The arguments were not sufficiently rigorous or recursive. In fact, what was very poorly tackled was the modern research on gender stereotypes and neuroplasticity. For what I can see, we are far from general consensus on whether there are such things as biologically, or innately, female or male brain. These have almost not been studied without the overarching influence of socialization, which as we know has a huge impact on the brain functions, preferences and basic personality traits. As Prof. G. Rippon points out in her bestseller (by the way beautifully referenced scientific literature) The Gendered Brain, modern neuroscience shows that any brain differences between males and females tend to be very small if there at all, and cannot most certainly account for the societal gaps between men and women. So clearly sociology and psychology play a more significant role. I felt this aspect was not even properly mentioned in this episode while it is so integral to the topic. How can one even start tackling what is “natural” about sex or gender, if we cannot even figure out what the potential differences are beyond genitalia are, if any at all? Many of these aspects are also discussed by A. Saini in bestseller Inferior, though it is more popular text. Maybe you can invite Prof. Rippon or Angela Saini to your series to broaden the discussion somewhat. I think it could really add a lot of scope.

    Also a small note about the pronouns. As a woman in science I also prefer the pronoun ´they’ purely, because it’s neutral and it removes the temptation for discrimination. For that reason I love the swedish language. It is known that language, culture and psychology are closely connected, so it’s not surprising one of the most gender equal cultures would naturally develop a language with almost no gendered forms and even brought in a neutral pronoun, which is being normally used. Eventhough I do identify as a biological woman, I conform to no gender stereotypes and especially in professional setting I prefer a completely neutral form of address, maybe because I have experienced first hand what gender discrimination brings.

    • Matt says:


      I wonder if the average 10% difference in brain size between men and women points to a more efficient female brain given the lack of difference in measured IQ between men and women. If a female brain is more efficient wouldn’t that be a notable sex based difference?

      Also I don’t believe in mind or brain body duality so I would say a female brain is a brain found inside a female body.

      When my daughter was 14 she learned in school that sex differences are irrelevant and minor and that how one identifies is much more important. When she was learning this she was getting used to her period which is not a minor impediment. She found the idea of elevating gender identity over physical sex differences galling due to the very real sex difference of a monthly period. Being a good dad I told her if she listened to her teachers about the irrelevance of sex based differences and simply identified as a boy during her period it would no longer be a problem. It took a few years but she came to see the humor in my dad joke.

  7. Michael F says:

    I have listened to the first three pods on this topic. You seem to be missing the huge elephant walking around. Everything psychology is biological. Primary sex characteristics might be binary for 99% of us. However that doesn’t mean that the brain isn’t wired differently. We have already found good scientific evidence of brain difference in sexual orientation. You alluded to spacial ability differences in gender. Therefore we can have very different brain wiring and construction based on gender, which has nothing to do with the person’s primary sex characteristics. Sex is one thing. Gender is another. Both have their roots in biology, someday I believe we will be able to test and see gender differences in the brain, regardless of what the sex is. Seemed like the talk became more philosophy and lost the thread that gender although partly constructed by culture is still hard wired in the brain and is part of our biology. It could be that someone who today we consider trans, in 50 years would could consider intersex based on prinatual hormones.

  8. M R says:

    First off, I just want to say what a huge fan I am of yours. I found your podcast about 5 years ago and I’ve been listening to you ever since. I really appreciate and value your insights. And this series is so well done! I believe everyone should hear it. I think it’s great how you’ve had people from all sides speak. And at times even challenged them on their beliefs in a nonaggressive way. I admire how eloquently you speak your mind in all your discussions.
    My only gripe is that I can’t help but feel some type of way every time I hear you promote BetterHelp. BetterHelp was anything but for me. I know I might be one in a million but if that’s true that only makes me feel worse lol. I kept hearing ads for them and had been thinking about going to therapy for a while. I’m pretty sure I used your promo code when signing up for BetterHelp but they were a mistake. 3 therapists, no help. First one only sent automated messages once a week that were clearly sent out to every client of theirs. Second therapist never responded, I waited for 2 weeks. Third therapist did not show up for our scheduled video session. After paying them for 2 months of therapy with no actual therapy when I could barely afford it in the first place I decided to give up on BetterHelp. False advertising, in my opinion.

    • Scott Barry Kaufman says:

      Wow thanks for this feedback. I’m sorry to hear about your experience with BetterHelp. I haven’t personally had that experience but that really is a shame though. I wish your experience was better with them, that’s for sure! Thanks for listening to my podcast.

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