Testosterone, sexual desire and courtship efforts association in young men | Hacker News Reader

Testosterone, sexual desire and courtship efforts association in young men

royalsocietypublishing.org

77 pointsgnabgib33 comments

When I had testicular cancer, they removed my cancerous nuts and put me on extremely close active surveillance as I underwent intense cancer treatment. One thing they checked for daily with blood work was my testosterone levels. Curious thing happened -- despite losing a ball, my testosterone shot way, way up. To the point where I was having weird symptoms like major migraines, I felt itchy all over my body, and just generally, not myself. The lust part was there for sure, but it was a confusing, scary time, being in cancer remission at 24.

Glad you're still here with us. How long did the levels stay elevated?

The key wording in the title and throughout the article is "day to day" testosterone associations.

If you understand what they are implying and not implying by that, the paper makes sense, but it is very poorly written in its omission of discussion of something it mentions only once in passing, the male circadian testosterone cycle (which it does describe how it tries to control for, but if you read this paper without understanding that, you won't really understand its findings.)

Women's hormones are well-understood to cycle monthly and it affects a variety of things including desire. What nobody ever told me growing up and the culture still doesn't talk about is that men, rather than having a monthly cycle have a daily cycle with huge testosterone swings that get lower in the afternoon and start rising dramatically in the early morning hours.[1]

This is something that correlates greatly with the "morning erection" and sexual urges (including porn) in the morning hours that many men experience. (And which at least some advertisers clearly understand, judging based on the ads shown to me at different times of day.)

As they themselves mention, "Our measures of sexual desire did not differentiate between dyadic and solitary desire", nor did they control for "solitary desire" activity and its impact on testosterone levels.

It is useful to have a study that looks at day-to-day testosterone as opposed to weekly/monthly/hourly, but I also found it frustrating there was no graph that showed based on their data how much testosterone fluctuated during the 31 days of month for their subjects (with some standard deviation bars or something). I know that wasn't what they were studying but I found it a bit hard to understand their findings without that.

[1] https://www.researchgate.net/figure/Serum-testosterone-conce...

I heard someone say once that testosterone makes doing hard things feel good. If that’s true, then it would align with the conclusions in this paper.

The paper proposes that testosterone's evolved function is more closely related to courtship efforts, than sexual desire.

It's easy to lust after a lady; not to court her.

If so, the purported purpose of testosterone makes sense, since the courtship process is hard.

I heard that from heuberman

For any discussion of this article keep in mind that this is the question being posed.

> Do fluctuations in men’s baseline testosterone concentrations predict changes in their sexual desire?

All the discussions about what happens when men have elevated testosterone beyond their baseline aren't really relevant. The answer should be interpreted as "men's testosterone doesn't fluctuate enough to statistically detect changes in sexual behavior."

This should be expected honestly because women do experience it and it's really obvious every month— you would know.

This is not a reasonable reading of this paper, and it also goes against what is already medically known about male hormone levels, which do indeed fluctuate. Men do have a hormone cycle. This paper doesn't dispute that - it merely makes the (possibly surprising) finding that a change in testosterone levels does not correlate with a change in sexual behavior.

It does, however, note that fluctuating testosterone levels still affect sexual desire, only it seems to show that an increase in testosterone predicts a reduction of sexual desire:

> While there was no significant cross-effect of sexual desire on testosterone levels in our data, there was an unexpected negative cross-effect of testosterone on sexual desire (electronic supplementary material, table S2). Specifically, higher levels of testosterone were associated with lower future sexual desire. This finding, contrary to our expectations, is displayed in the discrete-time plot of results (figure 2b), where cross-regressive estimates are standardized for interpretation. Shown by the testosterone-desire line (solid blue line), a 1 s.d. increase in testosterone predicted a significant decrease in sexual desire, peaking (estimate = −0.12) at around 0.7 days later.

men failed to self-report changes in sexual desire while experiencing normal cycles of testosterone levels, therefore testosterone does not affect sexual desire

There are no polite words for how utterly worthless this study is. The authors, the publisher, and anyone spreading this garbage should all be ashamed.

How would you design the study?

NTA but the study is pointless. Miniscule natural fluctuations of testosterone don’t increase sexual desire. The average fluctuation was 14.25 ng/dl. The subjects were aged 18-26. The average testosterone for this age range is probably around 500-700 ng/dl, so that’s a <3% fluctuation at the lower end. It’s minuscule.

They should have structured it by doing things that purposefully elevate testosterone naturally, that way the fluctuations would have been greater.

Right. It's like concluding that traffic congestion has no effect on mood after talking to a bunch of commuters whose commute time never varied by more than five percent during the study.

More than hormonal physiological effects, isn't psychological conditioning a much more dominant factor in consciously self-aware/acknowledged sexual desire? (Especially when it is being measured through self-reporting).

Until we invent some sort of non-obtrusive brain observability system (like a no-op continuous observability implant) that can take precise and accurate measurements with timestamps that can be correlated with other measurements taken across the boday of a person living their normal life, it is going to be difficult to form an effective study for this.

Every bodybuilder that has been through a testosterone cycle can attest to the drastic increase in lust. I have a hard time believing this study.

I only skimmed it so far but am having trouble believing it too. All their regression lines very clearly show a positive association between the variables, and it seems that they only failed to reject the null hypothesis because they didn't have a large enough sample size.

Also, regarding the bodybuilders, note that this study only measured the normal "day-to-day changes", and if we were to extrapolate their findings, it would likely show a much larger association when given exogenous testosterone.

Are you talking about ”normal” variations in testosterone like plus or minus 10-20% or like doubling?

Adding exogenous testosterone to the system might be very different than relying on the system's own T production.

It's reasonable that there are more homeostatic effects (upstream and downstream of the T) when you're just working with your body's own testosterone even if it's on the high end of the ref range. You'd skip that when you inject it.

The study was evaluating human-produced testosterone, not exogenous testosterone supplementation. If you take testosterone, it has been shown to increase sexual desire and is an approved treatment for sexual desire disorders. This is not what the study analyzed.

Are those body builders controlling for other variables? Changes in diet, exercise, performances, routines, etc?

I'd believe any number of things could correlate with body builders as they spend a lot of time changing their bodies.

I believe anecdotally that a lot of bodybuilders get on a T cycle after atleast a year or so of spending a lot of time in the gym natty. So noticing a relative difference might normalize for the other changes.

That's great! Not believing studies, I mean. They're not religious artefacts handed down by gods above

What you _can_ do, is read the study, especially the introduction, where it states what the study is about, the methods, which describe how the actual study went in real life, and the conclusion, which summarizes what we've learned from this.

After doing this, you can then maybe try a synthesis between the study thesis and your antithesis? Y'know, something a bit more substantial than a random drive-by comment

I did read the abstract. It did mention that they relied on internally created T but then the title is a bit misleading.

"I have a hard time believing this study."

Until the data has been scrutinized and the study replicated it's not worth paying a second of attention to.

Amphetamine, cocaine and so on commonly has a strong effect on "sexual desire and courtship efforts", so I've been assuming that testosterone and synthetic agonists has the same results through some indirect mechanism, if and when they do.

Not everyone on T and synths get those effects.

Alternative title: Testosterone fluctuations of <3% don’t have an impact on sexual desire (wow)

I’m not really sure what the point of this study is. Unless I’m not seeing it correctly (I skimmed it) this is just testing sexual desire based on natural testosterone fluctuations each day. The fluctuations are minuscule with the average being 14.215 ng/dl (unless I’m reading this wrong), which is expected.

Okay? People with natural day to day testosterone fluctuations don’t feel any dramatic effect on their sexual desire. Groundbreaking stuff.

I also cannot see the average testosterone of the meager 41 subjects which is a useful metric.

They could have used methodologies that are shown to purposefully fluctuate testosterone levels and tested that way. For example, being in the presence of an attractive woman spikes testosterone briefly. Poor sleep reduces testosterone, alcohol consumption decreases testosterone briefly. Doing a heavy weightlifting workout spikes testosterone briefly — and I can certainly attest to that in regards to sexual desire. Etc

Maybe the young men measured have low enough testosterone ranges that the high/low cycles have less effect, but the more likely explanation is that the methodology of this study is pretty laughable...

Whats laughable about it?

n=41 “Self reporting”

For starters. No information about the subjects other than their ages. I cannot see any information about their base testosterone levels either.

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