Psychological and Behavioural Effects of Endogenous Testosterone Levels and Anabolic-Androgenic Steroids Among Males: A Review, Part 8

"Joslyn (1973) has reported that injecting 3 infant female rhesus monkeys with 2mg of testosterone propionate intramuscularly 3 times per week over 8 months increased their aggressive behaviour so much so that they replaced males in top positions of the social hierarchy. Since this behaviour persisted for a year after the last hormone injection, the author suggests either that the male hormone may have directly induced a permanent change in the nervous system or alternatively that the socially dominant behaviour was so well learned during hormone treatment that it became independent of hormonal support."

That is fascinating.

Reply 10 likes

T seems to increase aggression by reduced activation of the orbitofrontal cortex, the neural circuitry of impulse control and self-regulation. But note that the effect size of T on a model of social aggression in humans is very small (r=0.35; barely significant). Higher testosterone in humans is related to aggression, social dominance, and hyperreactivity to status threats in both men and women. I have remarked before that I have a strong supposition that this is at the root of the romantic paranoia that users of tren often report (being "cucked" is the ultimate status threat).

Reply 2 likes

Yeah, the idea that permanent changes occur with limited AAS use is very interesting but also that researchers allowed for the possibility that the learned behavior is what changed the nervous system in the long-term.

I remember as a undergrad RA, my mentor was really excited by research showing that CBT could induce brain changes similar to that seen with meds.

I can totally see learned behavior (e.g. social/sexual confidence, etc) while on AAS persisting long after discontinuation in many users.

Reply 3 likes

preliminary findings raise the ominous possibility that long-term high-dose AAS exposure may cause cognitive deficits, notably in visuospatial memory.

Visuospatial function refers to cognitive processes necessary to "identify, integrate, and analyze space and visual form, details, structure and spatial relations" in more than one dimension.[1]

Visuospatial skills are needed for movement, depth and distance perception, and spatial navigation.[1] Impaired visuospatial skills can result in, for example, poor driving ability because distances are not judged correctly or difficulty navigating in space such as bumping into things.[1]

Reply Like

Same. I think that's what really intrigues me by that paragraph... I mean, which is it?

I have wondered about this before. Many times in fact. I've always described it as "primal switches in the brain getting flipped". I have come to a passive conclusion that the switches get flipped on but they never actually get flipped back off even when the stimulus is gone.

Very cool collection of articles, I've never come across them before and I'm not familiar with any of those authors either. Really enjoy these older articles getting bumped!

Reply 1 like