Female patients with varying grades of acne were examined to determine whether free testosterone levels were a more sensitive indicator of hyperandrogenism than total testosterone values. Of 24 women with acne studied, four were found to have elevated total testosterone levels, whereas 11 had elevated free testosterone levels. Twenty-four age-matched female control subjects without acne, hirsutism, or irregular menstrual cycles all had normal free and total testosterone values. The mean concentration of free testosterone in the patients with acne was ng/dL, while in the control subjects it was ng/dL. Other than hirsutism in three patients with acne with elevated free testosterone levels, there were no morphologic clues identified to determine which patients with acne are more likely to have abnormal free testosterone levels. The free testosterone level did not correlate with the type, distribution, or severity of the acne present in the patients.
The second theory is similar and is known as "evolutionary neuroandrogenic (ENA) theory of male aggression".   Testosterone and other androgens have evolved to masculinize a brain in order to be competitive even to the point of risking harm to the person and others. By doing so, individuals with masculinized brains as a result of pre-natal and adult life testosterone and androgens enhance their resource acquiring abilities in order to survive, attract and copulate with mates as much as possible.  The masculinization of the brain is not just mediated by testosterone levels at the adult stage, but also testosterone exposure in the womb as a fetus. Higher pre-natal testosterone indicated by a low digit ratio as well as adult testosterone levels increased risk of fouls or aggression among male players in a soccer game.  Studies have also found higher pre-natal testosterone or lower digit ratio to be correlated with higher aggression in males.     
Perhaps one of the most confusing things for men to find out is whether or not they have Low T. Every lab has its own range of what is considered “normal.” That is why a man should always turn to a hormone specialist for a diagnosis of low testosterone. The normal testosterone levels age chart may vary significantly, and what is considered normal for one lab or medical clinic may not be for another. The HRT specialist will also look at your symptoms and their severity when determining a diagnosis and treatment protocol to prescribe.