Score Discrepancy Between Verbal IQ and Performance IQ
By Inderbir Kaur Sandhu, Ph.D
Can you please explain the scores discrepancy. If its only says
1. VIQ > PIQ
2. PIQ > VIQ
3. If PSI and working memory both in low range but VIQ and PIQ are in
average range with attention issues reported.
In a normal population, the expected mean VIQ-PIQ discrepancy is zero (VIQ
is short for Verbal IQ and PIQ is Performance IQ). When there is a large
discrepancy between verbal and performance IQ, it generally points out
to a learning difficulty or overcompensation and/or impairment of some
kind. For instance non-verbal learning difficulty (NVLD) is usually
suspected when there is a high VIQ-PIQ difference (VIQ>PIQ).
Usually when a discrepancy of at least 12 points is found between the
VIQ & PIQ, the Full Scale IQ score should be interpreted cautiously.
Even though the verbal-performance discrepancy is not used to directly
diagnose a learning disability, it is like a red flag – it alert parents
and teachers to the child's strengths and weaknesses. Therefore, a full
analysis of the individual subtests that comprise each score should be
looked at and if scatter is very large, it warrants further
Research has indicated that a discrepancy towards verbal (VIQ > PIQ) has
also been linked with Asperger's syndrome but not with other pervasive
developmental disorders. Relatively low VIQ has been considered an
indicator of dyslexia and relatively low PIQ of dyspraxia. Studies have
also suggested that hyperactivity in children is associated with
relatively low performance IQ. In more recent studies, it is found that
there is a high degree of individual and familial comorbidity between
these three disorders.
The term clinically significant means that the severity of the
behaviour/performance is significantly different from the norm and
indicates a strong possibility of a clinical problem.
Hope that helps. Good luck!