I was recently asked the following question by a parent, “What does the FSIQ score mean?”.   The parent had recently had their child evaluated by the school psychologist.

Many people are under the impression that the IQ score expressed as the Full Scale IQ  Score (FSIQ) is “destiny” for their child. In my practice, I have sat across the table from parents and explained the meaning of the intelligence assessment. Their minds are filled with questions and concerns.  My goal in these situations is to confirm the strengths or weaknesses that parents or teachers see in the everyday functioning of the child.

Background Information: On the WISC-V, a commonly used instrument, The FSIQ is comprised of discrete indices:

  • Verbal Comprehension Index (VCI)
  • Visual Spatial Index (VSI)
  • Fluid Reasoning Index (FRI)
  • Working Memory Index (WMI)
  • Processing Speed Index (PSI)

Below is an explanation of each index.

The Verbal Comprehension Index (VCI) assesses your child’s ability to understand, define and reason with words.


1) Is your child good at expressing themselves verbally?

2) Is your child capable of using words effectively and explaining the differences between words.

The Visual Spatial Index assesses your child’s ability to reason in a visual, “hands-on” and concrete manner.


1) Is your child good at constructing objects with Legos or the Rubics cube? Both of these objects are concrete and provide immediate feedback similar to the VSI index.

The Fluid Reasoning Index assesses your child’s ability to determine the relationship between visual objects. This scale evaluates one’s ability to think “bottom up” and “top down” (inductive and deductive) reasoning. Furthermore, it also incorporates mathematical reasoning as well as the ability to think flexibly.


1) Is your child good at looking at a completed puzzle (full picture) and then    figuring out   the missing piece in their own construction?

2) Can your child figure out how much water is needed to fill two jars placed upon a scale to keep it balanced?

The Processing Speed Index assesses your child’s ability to visually scan information rapidly and reproduce it within a time limit. In this index, speed and accuracy are vital.


1) Can your child write legibly and accurately?

2) Can your child copy notes effectively from a board when a lecture is moving fast?

When these indices are combined, they yield a Full Scale IQ score that can be useful in answering questions such intellectual giftedness, intellectual deficiencies, and learning deficits.  Keep in mind that an IQ score usually has mathematical error built into it.  Listed below are a few of the take home messages.

  1. IQ is not “destiny”.  The score represents a picture of your child that is mostly constant over time.
  2. Think of your child’s scores as a profile comprising strengths and weaknesses. We can always use a strength to develop an area of deficit.  If the strength is visual spatial skills, then we can use a visual format to learn verbal information.
  3. Remember that intelligence testing does not assess motivation to succeed or social skills.  It is one piece of a whole that can help answer specific questions.

I hope I was able to answer the question of intelligence testing.  If you have any further questions pertaining to this area, please do not hesitate to ask.  This is a broad area that I can spend hours explaining.  I hope it empowers parents to feel less intimidated when trying to comprehend what these scores mean.