Reliability and Validity of Draw-a-Person Test and Gesell Drawing Test for Assessing Intelligence in Children Aged 6-12 Years Old

Background: Intelligence assessment is important in pediatric practice, but standard IQ tests require administration and interpretation by clinical psychologistsand time-consuming. Alternative tools, such as the Draw-a-Person and Gesell Drawing Tests, are feasible and not limited by language. However, evidence of their reliability and validity remains limited, particularly in Thailand. Objective: To determine Reliability and Validity of Draw-a-Person Test and Gesell Drawing Test for Assessing Intelligence in Children aged 6-12 years old Method: A cross-sectional study was conducted at Songklanagarind Hospital, including 86 children aged 6–12 years who had completed a standard IQ (WISC) test. Children with fine motor problems or uncorrected visual impairments were excluded. Participants performed the Draw-a-Person and Gesell Drawing Tests, which were scored by researchers who blinded to the standard IQ results. Inter-rater reliability was assessed in 30 cases by three independent raters (general practitioner, pediatric resident, and clinical psychologist). Validity and correlation of the drawing tests with the standard IQ test were subsequently analyzed. Result: Of the 86 participants, 70% were male, and the median age was 9 years. The most common diagnoses were ADHD (51%), learning disorders (28%), and autism (14%). Mean IQ scores from the Gesell Drawing Test were close to the standard IQ, whereas the Draw-a-Person Test tended to yield higher scores. Distribution analysis showed that both the Standard IQ test and Gesell placed most children in the borderline range (IQ 70–89), while the Draw-a-Person Test produced higher scores. Inter-rater reliability demonstrated moderate agreement for the Draw-a-Person Test (ICC 0.6) and good agreement for the Gesell Test (ICC 0.76), both statistically significant. Using an IQ cut-off of <70 to define intellectual disability, the sensitivity of the Draw-a-Person and Gesell Drawing Tests was 40% and 60%, whereas specificity was high at 83% and 93% Correlation analysis revealed that the Gesell Test had a moderate positive correlation (r=0.57) with standard IQ, while the Draw-a-Person Test showed only a weak correlation(r=0.4). A positive moderate correlation was also observed between the two drawing tests. Conclusion: Both the Draw-a-Person and Gesell Drawing Tests demonstrated moderate to good reliability, low sensitivity but high specificity, and a positive correlation with standardized IQ scores. While these tools may be useful for preliminary screening, their application in clinical practice should be undertaken with caution.