Another popular myth is that because testosterone propionate is a short ester based steroid, it is not as effective in bodybuilding as other variants like enanthate or propionate, which are long ester based steroids. Actually, all these steroids have testosterone as their active ingredient, and the way it acts on the body’s anabolic system does not change with variants. In fact, when measured per 100 milligrams of each variant compound, it is seen that propionate contains more amount of testosterone than cypionate or enanthate. For example, while propionate contains 83mg of testosterone, the other variant cypionate is seen to contain only 70mg of the same . Ultimately, by adjusting the dosages of various types of testosterone, you can gain the same kind of results.
Testosterone is significantly correlated with aggression and competitive behaviour and is directly facilitated by the latter. There are two theories on the role of testosterone in aggression and competition.  The first one is the challenge hypothesis which states that testosterone would increase during puberty thus facilitating reproductive and competitive behaviour which would include aggression.  Thus it is the challenge of competition among males of the species that facilitates aggression and violence.  Studies conducted have found direct correlation between testosterone and dominance especially among the most violent criminals in prison who had the highest testosterone levels.  The same research also found fathers (those outside competitive environments) had the lowest testosterone levels compared to other males.