Vol. 8, No. 3, 2002 Page 3

Spatial IQ deficits in toddler years associated
with persistent antisocial behavior

Low verbal IQ is considered an early risk factor for antisocial tendencies. A new study, however, suggests that deficits in spatial IQ appear before kindergarten age in persistently antisocial children, predating the deficits in verbal ability.

Adrian Raine and colleagues studied 330 children (177 males and 153 females) participating in a long-term study of a cohort of children born in Mauritius in 1969. The presence or absence of antisocial behavior had been assessed when the children were 8 and 17 years of age, and their IQs were measured at the ages of 3 and 11. Scholastic and reading ability also were measured when the children were 11.

Raine and colleagues report that the persistently antisocial children (those who exhibited antisocial behavior at both 8 and 17 years of age) exhibited spatial IQ deficits, but not verbal deficits, at the age of three. By the age of 11, they exhibited both spatial and verbal IQ deficits. These findings were true for both males and females and remained significant when the researchers controlled for social adversity and poor scholastic ability, and for hyperactivity, poor motivation, and distractibility during the initial testing period.

"A key finding from this study is that persistent spatial cognitive deficits are specific to persistently antisocial individuals," the researchers say. "While childhood-limited and adolescent-onset groups both show cognitive deficits at one age but not another, only the persistently antisocial group showed significant cognitive deficits at ages 3 and 11 years."

The researchers say their data are consistent with other research, noting, "[T]he few longitudinal studies starting in preschool years tend to find more evidence for spatial than verbal deficits in antisocial children from community samples." This is particularly true, they say, for children whose antisocial behavior is persistent rather than transitory.

Spatial IQ deficits are likely to stem from right hemisphere impairment, leading Raine et al. to propose an "early starter" model in which "early visuospatial (right hemisphere) impairments can predispose to persistent antisocial behavior by interfering with early attachment and emotion recognition and regulation." Among the possible mechanisms the researchers suggest:

Moreover, the researchers say, early right hemisphere dysfunction may lead to a reorganization of the brain, in which the left hemisphere takes over some spatial functions in addition to its normal verbal functions, possibly "crowding" the left hemisphere and increasingly compromising verbal abilities. "Such a perspective," they say, "may help explain why studies of adolescent delinquents find stronger verbal than spatial deficits."


"Spatial but not verbal cognitive deficits at age 3 years in persistently antisocial individuals," Adrian Raine, Pauline S. Yaralian, Chandra Reynolds, Peter H. Venables, and Sarnoff A. Mednick, Development and Psychopathology, Vol. 14, No. 1, Winter 2002, 25-44. Address: Adrian Raine, Department of Psychology, University of Southern California, Los Angeles, CA 90089-1061, raine@usc.edu.

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