IQ Part 1: Verbal Comprehension
In my last post, I discussed in general terms how IQ is calculated. When broken down, the overall IQ is comprised of various cognitive aspects we all possess. Today I want to examine Verbal Comprehension, its make up, and how it impacts the overall IQ.
For the purposes of my post, I will discuss Verbal Comprehension as a component of the WISC-V. The WISC-V is the main cognitive assessment I give to most of my patients, and it is geared towards kids (ages 6-16) rather than adults. However, the WAIS-IV (used to assess adults) also contains a Verbal Comprehension component that is very similar to that of the WISC-V.
What is Verbal Comprehension?
In my neuropsychological reports, I describe Verbal Comprehension as: “Verbal Comprehension measures the individual’s ability to access and apply acquired word knowledge.” The three important words in this description are:
Acquired
Access
Apply
Individuals who possess a strong Verbal Comprehension not only learn an increasingly complex vocabulary (“acquired”), but they also have the ability to recall it (“access”) and use it in correct context (“apply”). There have been some studies done questioning the validity of Verbal Comprehension as a component of the overall IQ, but most agree that the ability to utilize vocabulary sufficiently is crucial to measuring one’s cognitive ability.
How is It Calculated?
The Verbal Comprehension index score is comprised of two main subtests: Similarities and Vocabulary. These two subtests are widely used in the computation of the overall IQ.
The Similarities subtest requires the child to hear a set of words and then describe how those two words are similar. For instance, the examiner will say, “How are a cookie and a cake alike?” The child earns either 0, 1, or 2 points based on his or her response. A 1-point answer would be something like, “They are both round.” A 2-point answer would be, “They are both types of dessert.” A 0-point answer is entirely incorrect, either because the child does not know one or both of the words, or he or she guesses incorrectly.
The Vocabulary subtest asks the child to give the definition of a word. For instance, the examiner might ask, “What is a desk?” These items are also scored either 0, 1, or 2. A 1-point answer would be something like, “It’s a table.” A 2-point answer would be, “It’s a table where someone does work.” As you can see, details and elaboration are essential to a good score.
On both subtests, the examiner can prompt the child to give more information if necessary. However, the examiner cannot offer additional information or hints.
There are two additional tests as well that can be used as substitute tests for the overall IQ or just as additional tests to get a deeper look at an individual’s Verbal Compression: Information and Comprehension. Sometimes I use the Information subtest, which asks a series of questions to gauge the child’s overall knowledge base. I rarely use the Comprehension subtest, which requires a child to make inferences from verbal prompts, although in certain situations it can lend additional insight into a child’s Verbal Comprehension.
Once subtest scores are obtained and summed, the examiner then converts them to a standard score:
130 or above: Very Superior
120-129: Superior
110-119: High Average
90-109: Average
80-89: Low Average
70-79: Borderline
Below 70: Extremely Low
Keeping in mind that a standard score of 100 is exactly in the middle of all examiners of the same age range as the child, the majority of students I test fall into the 80-120 range.
What Does the Score Tell Us?
Quite a bit can be interpreted from one’s Verbal Comprehension score. For instance, I get many referrals for evaluation for possible dyslexia, and a child’s Verbal Comprehension score is critical to determining whether or not dyslexia exists. Children who have dyslexia often times have a relatively high Verbal Comprehension (cognitive ability) compared to their ability to read (academic ability). This discrepancy between cognitive verbal ability and academic verbal ability is a typical indicator that an underlying learning disorder (i.e., dyslexia) is at play and warrants further investigation.
Additionally, understanding an individual’s Verbal Comprehension can help steer him or her in the right direction in terms of school and/or career. Recognizing strengths and weaknesses and learning to use them to one’s advantage is a game changer for those who have struggled in the past. When examined in relation to the other index scores on the WISC-V, one can begin to see cognitive patterns that demonstrate these strengths and weaknesses. Children with strong Verbal Comprehension often times excel in activities such as speech and debate and student government and may experience academic success in classes such as English, social studies, and languages.
In my next post we will look at the next component of the IQ: Visual Spatial.