Expanding upon the 'extreme male brain' theory of autism as a common link between other major risk factors: a hypothesis.

On average, males have a stronger preference for physical systems and machines over interpersonal interactions; they have lower average levels of cognitive empathy or social cognition than females; and they have higher rates of 'extreme' intelligence when it comes to abstract concepts such as those found in mathematics and sciences. All three traits are also commonly associated with individuals with an autism spectrum disorder or ASD; clearly, it is not coincidental that incidence rates of autism are reportedly four times higher in males than in females. The common link between the majority of risk factors assessed in this review (including technological advancements, advanced parental age, socioeconomic status, and genetic predispositions towards ASDs in families of scientists and engineers) can be traced to a specific hormone, testosterone. It was established that traits which are typically associated with males are also typically associated with ASDs as well as individuals with antisocial personality disorder, or APD. The key distinction between individuals who are considered to be 'autistic' as opposed to those who are considered 'sociopathic' lies in the difference between their empathy deficits: whereas those who are 'autistic' are said to lack cognitive empathy (the ability to identify and understand the thoughts and feelings of others and to respond to these with appropriate emotions), those who are 'sociopathic' are said to lack emotional empathy (which is responsible for inhibiting acts of physical aggression or violence). This would explain why autistic individuals can have elevated testosterone levels without becoming physically aggressive.