Objective: Standardized intelligence quotient (IQ) tests are useful measures of cognitive functioning; nonetheless, their applicability in general pediatric practice remains limited. Accordingly, the Gesell Figure Drawing Test was used for preliminary IQ assessment. This study evaluated the validity of the Gesell Figure Drawing Test in measuring IQ compared with standard tests among children aged 6–10 years.
Material and Methods: This cross-sectional study recruited children aged 6–10 years who underwent IQ testing at at the Pediatric Outpatient Department of Songklanagarind Hospital. Each child completed the Gesell Figure Drawing Test with a psychologist, followed by a standard IQ assessment (either the Wechsler Intelligence Scale for Children or Stanford-Binet LM) administered by another psychologist blinded to the Gesell Test results. The IQ scores obtained from the Gesell Figure Drawing Test and standard tests were compared to determine test validity. Inter-rater reliability was assessed by comparing the Gesell Test IQ scores obtained from three independent raters.
Results: Of the 59 participants, 43 were male (72.9%), and the mean age was 8.6 years (standard deviation, 1.1 years). Inter-rater reliability exhibited intra-class correlation values ranging from 0.70 to 0.84 across the three raters. The sensitivity, specificity, positive predictive value, and negative predictive value of the Gesell Figure Drawing Test to detect participants with IQ scores <70 were 87.5%, 80.4%, 41.2%, and 97.6%, respectively.
Conclusion: The findings of this study support the favorable psychometric properties of the Gesell Figure Drawing Test for assessing IQ in children 6–10 years of age.