" Thus we are trying to compensate for the serotonin deficiency and to lower the level of cortisol.

I agree but. (imo) Its also a testosterone thing. But you already saying that. Because the lower the cortisol gets the more testosterone a man/women can produce?

If you have other reliable sources of serotonin you will not want to show off!

I think i see your point and you are def right people with high testo/sero can be very calm.

However if you work out serotonin rises big time. right? Then why would people pumped up in the gym wanna show of? imo they are high on dopamine, serotonin, testosterone. And the last thing those gym rats wanna do is to not show of.. :)