CHARACTERISTICS OF 12TH-GRADE STUDENTS SERIOUSLY DEFICIENT IN SPATIALABILITY

When spatial ability was regressed on a measure of general intelligenc e in a large national sample of 12th-graders, there was a distinct dow nturn in the regression line at about -2 SD units. A bimodal distribut ion of spatial ability was found among these low scoring students, sug gesting 2 qualitatively different types of individuals. Relative to st udents of expected spatial ability, those below expected in spatial ab ility were high on verbal skills and low on performance skills. Studen ts unexpectedly low in spatial ability performed relatively well on co gnitive tests that required answering unambiguous questions by retriev ing information directly from long term memory, whereas they performed relatively poorly on tests requiring inference and perception of rela tions among novel stimuli. Students unexpectedly low in spatial abilit y performed especially poorly at tests involving visual-spatial percep tion skills. Results were similar for both sexes. The relatively poor performance of those unexpectedly low in spatial ability does not appe ar to be related to health problems, personality, interest differences , or biographical data. An organic impairment possibly related to late ralization represents a reasonable causal hypothesis for these data.