The Neurodiversity of Sherlock

OK I admit it.  I am an obsessive fan of the BBC’s Sherlock series.  As a neuroscientist I’m in love with breaking down complex questions with logic, and indulging in each episode gives me the opportunity to do so late into the evening.  

The series is a modern-day reinterpretation of the classic Sherlock Holmes stories by Arthur Conan Doyle, and revolves around the extremely intelligent “consulting detective” Sherlock Holmes and his partner John Watson, who together attempt to solve otherwise unsolvable crimes.  I especially find the way the writers define each character particularly fascinating.  Where Sherlock obsesses over his work for the sake of solving each mystery, John often focuses his attention on solving each case to benefit those involved.  The writers present seeming personality dichotomies that surprisingly coalesce and complement one another.

I am particularly intrigued by the way the main characters construct and develop their own mental states over the course of the series.  For instance, in the midst of an investigation in the show’s first episode, Sherlock sneers at a police forensic scientist who calls him a psychopath: “I’m not a psychopath, Anderson.  I’m a high-functioning sociopath. Do your research.” ("A Study in Pink", 2010) It’s a great line, but there’s also something not quite right about it.

As it turns out, sociopathy and psychopathy are essentially the same disorder. Both are informal and somewhat outdated variants of what became known as Antisocial Personality Disorder (ASPD), which is characterized by a disregard for social norms, frequent lies, impulsive behavior, aggressiveness and hostility, irresponsibility and risk taking, and a remorseless indifference to the feelings and rights of others (for more, see and

Why does Sherlock purposely confine himself to this narrowly defined personality?  How does this early self-definition shape our future expectations and responses to his actions, and why does he even correct Anderson if sociopathy and psychopathy are essentially one in the same? Perhaps Sherlock does not really consider himself sociopathic, and facetiously corrects Anderson as an indirect attack against arrogant pseudo-intellectualism, especially in light of the fact that sociopathy is no longer classified as a personality disorder under the DSM-V (Gunderson, J. 2013. Personality Disorders: Theory, Research and Treatment)

Indeed, this theme of false neuropathology exists with other characters in the Sherlock series as well – notably John Watson, who in the first episode claims his limp is a consequence of a war injury, until Holmes proves to him that the limp is simply a psychosomatic manifestation (i.e. a mental creation) connected to post-traumatic stress disorder (PTSD) (“A Study in Pink", 2010).  Keeping this in mind, I (and others)  have compared Sherlock’s behavior against the typical traits of someone with ASPD, and it appears Sherlock’s self-diagnosed sociopathy is also a false one.  Where sociopaths typically have little to no inter-personal emotion and empathy, Sherlock clearly understands and displays intense emotions for others (especially John and their dear landlady, Mrs. Hudson), but simply rationalizes that more often than not those emotions interfere with his logical reasoning (“The Great Game”, 2010).    


No, Sherlock is probably not a sociopath, but he certainly does have questionable and eccentric behavior.  Yes, his ability to filter out distracting information helps polish his brilliance, but also often prevents him from picking up on relevant social cues.  In many ways, Sherlock may actually align closely with another psychiatric condition - Asperger’s Syndrome, an ill-understood Autism Spectrum Disorder (ASD) marked by limited or reduced verbal and non-verbal social communication, repetitive and unusual interests and areas of expertise, and occasional behavioral misconduct (i.e. aggression) (McPartland & Klin. (2006). Adolesc Med).

I wonder whether the show’s writers focus on Sherlock’s eccentric behaviors in part to push us to critically analyze and reevaluate our expectations of his future actions, as well as to force us to reconcile with our current standards of the abilities and limitations of those with mental illnesses.  It is crucial to note that the real strength of the writing revolves around our perceptions (and misperceptions) of these extremes.  Taking this one step further, the writing might even beg us  to question what the normal social conventions defined in the series really are, and what this means for our own social surroundings.

You may have read recently about the notion of Autism Rights – aka: Neurodiversity – a new movement that likewise questions such stereotyped social norms.  The movement is a response to the large population of neurodiverse individuals that are a part of our regular social environment, and it challenges the categorical definitions of autism and related disorders by instead advocating that these differences (or neurodiversities) are simply functional variations of ‘normal’ mental states (Cascio, M. A. 2012. Intellectual and Developmental Disabilities).  

Rather than focusing on treating abnormal behaviors associated with autism-spectrum disorders (ASD), Autism Rights accepts – even glorifies – these behaviors.  It argues that just as homosexuality used to be diagnosed as a mental illness, perhaps we are also erroneously defining behaviors included in ASD as mental illnesses and should instead focus on the strengths, unique talents, and overall humanism of those with these syndromes.  Specifically, the movement emphasizes respect for autonomy, comprehensive social integration, and equal rights for those with ASD, and further asks that we generally accept “mental disabilities” as part of our normal socially diverse environment (Robertson, S. 2010. Disability Studies Quarterly). 

Analogous to this new movement, Sherlock and John Watson are ironically the heroes of the show, despite the convention that sociopathy, PTSD, Asperger’s Syndrome, and other such disorders are usually considered neuropsychological maladies.  During each 1.5 hour long episode, Sherlock and John’s personalities and mental landscapes become commonplace; they take the center stage and cloud the otherwise “normal” and “common” personalities of the supporting characters.  These extreme psychologies become so central that the word “disorder” begins to detach itself from them.  The writers of the show cleverly pull us into the inner-workings of each character’s mind; we solve each mystery alongside Sherlock and absorb his thoughts into our own.  We might understand why Sherlock’s often erratic behavior may be deemed unnatural, but learn to appreciate it for what it is.  Perhaps the writers are suggesting that we should readjust our definitions of maladaptive neurospsychological disorders and broaden the boundary between individualism and illness. 

I am thrilled that neuroscience is becoming increasingly accessible to the general public – via expanding neuroscience educational outreach, integration into media through shows such as Sherlock, and even budding new fields such as Social Neuroscience, a branch of neuroscience devoted to understanding how our brains process and integrate social interactions (Cacioppo, J. & Bernston, G. 1992. American Psychologist).  But because of this accessibility, I know how vital it is that we think about neuroscience with critical and open minds.  The writers of Sherlock may be doing just that, and persuading us to do the same.  This flowering idea of “neurodiversity” could do worse than to have Sherlock as an exemplar.