Unit for the Study of Personality in Politics

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Eric Harris: Developmental Considerations

Aubrey Immelman

 August 2004

All patterns of pathological personality . . . comprise deeply etched and pervasive characteristics of functioning that unfold as a product of the interplay of constitutional and experiential influences. The behaviors . . . that evolve out of these transactions are embedded so firmly within the individual that they become the very fabric of his or her makeup, operating automatically and insidiously as the individual’s way of life. (Theodore Millon, 1996, p. 609)

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The core component of Eric Harris’s personality is the dominant pattern, which in its most maladaptive form presents as sadistic personality disorder, characterized by unconstrained aggression. Harris’s personality profile also includes narcissistic and antisocial features and possibly paranoid traits. 

The Dominant Pattern (Sadistic)

MIDC Scale 1A: The Dominant Pattern

The Dominant pattern, as do all personality patterns, occurs on a continuum ranging from normal to maladaptive. At the well-adjusted pole are strong-willed, commanding, assertive personalities. Slightly exaggerated Dominant features occur in forceful, intimidating, controlling personalities. In its most deeply ingrained, inflexible form, the Dominant pattern displays itself in domineering, belligerent, aggressive behavior patterns that may be consistent with a clinical diagnosis of sadistic personality disorder.

Tracing the origins of Eric Harris’s personality requires an examination of the characteristic developmental history of the dominant, aggressive personality pattern. It should be recognized, however, that personality is a complex, multi-determined construct. For example, there are hereditary and other biogenic (inborn, constitutional) factors that are too inscrutable or speculative to warrant definitive conclusions. The present examination therefore emphasizes experiential family history, which is often sufficient to prompt a particular personality style.

In this regard, the critical question relates to the nature of Eric Harris’s temperament as an infant. Temperament refers primarily to one’s inborn predisposition to activity (active vs. passive) and emotionality (positive vs. negative affect). Sadistic tendencies can be rooted temperamentally in a predisposition to high activity level combined with negative emotionality — in other words, a restless, cranky baby prone to crying and staying awake for extended periods. A difficult-to-manage infant with a testy, sullen, choleric temperament is prone to prompting parental hostility. According to Theodore Millon, the primary biogenic factor underlying an aggressive or sadistic personality style is a “choleric infantile reaction pattern.” Millon (1996) explains the hypothesized pathogenic effect of a choleric infantile reaction pattern as follows:

Parents often complain that their child displayed temper tantrums [crabby, prickly, fractious behaviors] even as an infant. . . . [G]iven a “nasty” disposition and an “incorrigible” temperament from the start, these youngsters provoke a superabundance of exasperation and counterhostility from others. Their constitutional tendencies may, therefore, initiate a vicious circle in which they not only prompt frequent aggression from others, but, as a consequence, learn to expect frequent hostility. (p. 496)

Concerning the characteristic family history of aggressive persons, Millon emphasizes parental hostility — which, it must be noted, can be prompted by a difficult-to-manage infant born with a testy, sullen temperament (i.e., an interactional effect of dispositional and environmental variables). Inborn disposition aside, children sometimes serve as a convenient scapegoat, or “lightening rod,” for parental anger arising from occupational, marital, or social frustrations. Rather than manage their anger directly and appropriately, these parents vent their anger on their children in a maladaptive coping strategy known as “displacement.”

According to Millon (1996), chronic exposure to parental rejection — typically teasing, belittlement, and humiliation — results in a view of the world as hostile and dangerous and breeds a suspicious if not paranoid outlook on life. Most children subjected to this treatment come to view themselves as weak, worthless, and beneath contempt; they ultimately develop a timid, insecure, avoidant personality style. Some children, however, perhaps by nature more resilient and hardy, learn instead to believe they are a power to contend with. To their way of thinking, they are sufficiently potent to influence others’ moods and actions — that they have the capacity to create distress. Adding injury to insult, parental hostility, in the intense anger and resentment that it generates in a child, can ultimately breed counterhostility (p. 497).

The psychogenesis of the aggressive style is encapsulated in Millon’s assertion that these personalities “go out of their way to denigrate any values that represent what they themselves did not receive in childhood.” Thus, they become untrusting and harsh in their interpersonal relationships and the world at large; they are persistently on the defensive and any cracks in their tough outer facade or perceived exposure of personal weakness or inner vulnerability prompts capricious, precipitous surges of hostility and outbursts of rage.

In summary, an aggressive/sadistic personality typically is forged from an inborn predisposition — a choleric infantile reaction pattern — combined with the hostility it evokes in parents (Millon, 1996, pp. 496–498).


Millon, T. (with Davis, R. D.). (1996). Disorders of personality: DSMIV and beyond (2nd ed.). New York: Wiley.

Related Reports

Eric Harris: Personality Profile (August 2004)

Indirect Evaluation of Eric Harris (April 30, 1999)
[Warning: explicit, violent, offensive language]

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Last updated November 24, 2007