Notice that the American Egg Board’s statement cannot be contested as false. They’ve found a way to be technically truthful, while causing many readers, including you, to think they’re saying something they’re not. This skill is a technique of successful advertising, and we should all become aware of it. We, the public, can benefit by learning to read carefully and think critically about what others, be they industries agencies or individuals, are actually saying as opposed to what they want us to think they’re saying.
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.