A series of papers by J. Arturo Silva and colleagues suggests that some serial killers—including Jeffrey Dahmer and Theodore Kaczynski (the "Unabomber")—exhibit evidence of Asperger's disorder (AD), a variant of autism.
Autism is a neurological disorder that severely affects communication, social skills, behavior, and learning. Individuals with AD are far less impaired mentally and socially than other autistic individuals, and often are highly intelligent. Unlike people with autism, individuals with AD exhibit normal language development, although their speech tends to be somewhat eccentric. While very few people with AD are violent, studies do suggest that the prevalence of AD may be elevated in violent criminal populations.
Silva et al. say that Dahmer, convicted of serially killing and cannibalizing young boys, exhibited signs of AD from his earliest years. As a child, he exhibited poor eye contact, displayed facial expressions "devoid of emotional glow," had a rigid body posture and gait, and was isolated, socially inept, and "emotionally disconnected." He also strongly disliked change and was highly ritualistic and obsessive (with his obsessions including the collection of bones and dead animal bodies). All of these traits can be signs of AD.
Silver et al. argue that Dahmer's creation, collection, and utilization of cadavers can be viewed as "a sexualized form of the repetitive behavioral patterns typically encountered in AD." Dahmer's treatment of his victims, they say, is consistent with the fact that individuals with AD have trouble both in "theory of mind" (the understanding that other people have thoughts and feelings) and in distinguishing between people and objects.
Similar patterns, Silva and colleagues say, appear in the history of Kaczynski, who killed three people and wounded dozens by sending them mail bombs. Silva et al. note that Kaczynski was aloof and could not understand the feelings of others. He also exhibited an aversion to being touched and experienced extreme distress when exposed to noise, both common reactions in children with autism. A neighbor described the young Kaczynski as "a child who was an old man before his time," consistent with Hans Asperger's description of his young patients with AD as "little professors," and as an adult, Kaczynski was extremely impaired in social relationships. Kaczynski's preoccupations with bomb-making and the perceived evils of technology, the authors say, can be viewed as typical of the obsessive interests of a person with AD.
Silva et al. say their characterization of a subset of serial killers as having high-functioning autism could lead to a greater understanding of the etiology of both serial homicide and autism. "Psychological phenomena of central importance to understanding serial killers such as deficits in empathy have frequently been explained as originating from a psychopathic core," they say, "thereby missing the possibility that deficits in empathy may also be due to autistic psychopathology."
"A neuropsychiatric developmental model of serial homicidal behavior," J. Arturo Silva, Gregory B. Leong, and Michelle M. Ferrari, Behavioral Sciences and the Law, Vol. 22, 2004, 787-99; and "The case of Jeffrey Dahmer: Sexual serial homicide from a neuropsychiatric developmental perspective," J. Arturo Silva, Michelle M. Ferrari, and Gregory B. Leong, Journal of Forensic Sciences, Vol. 47, No. 6, 2002, 1-13; and "Asperger's disorder and the origins of the Unabomber," J. Arturo Silva, Michelle M. Ferrari, and Gregory B. Leong, American Journal of Forensic Psychiatry, Vol. 24, No. 2, 2003, 5-43. Address for all: J. Arturo Silva, P.O. Box 20928, San Jose, CA 95160, firstname.lastname@example.org.