Icon for The Psychological Testing Center of San Francisco

The Unspoken Importance of IQ

IQ stands for Intelligence Quotient, a term which describes the score obtained from several standardized tests designed to assess human intelligence, based upon large statistical studies. In fact, the most common IQ test, the Wechsler scale, bases Full Scale IQ on four statistically derived factors: Verbal Comprehension, Perceptual-Reasoning, Working Memory, and Processing Speed. While the identification of IQ is controversial in our politically-correct society, knowing a student’s IQ is essential in understanding the cognitive profile and functioning of a student. In lay terms, these domains of intelligence break down in to: language and verbal skills coupled with abstract reasoning, visual puzzle-solving abilities, memory, and speed of processing. This intuitively makes sense, given that we think of people as smart when they: have a big vocabulary, know lots of esoteric facts on a broad range of topics, can solve abstract visual puzzles, remember and mentally manipulate information well, and process information quickly.

The full range for IQ is from 50 to 160; below 70 connotes severely mentally impaired and above 130 is genius. I chuckle when people mention that they have taken an on-line test and scored a 165, given that the scale does not even go that high. In assessing over 1200 students, the highest IQ I have ever seen is a 145, which is extremely rare –by definition. In fact, IQ’s over 130 occur in only 1 in 100 students. The average IQ ranges from 90 to 110, with 80-90 being low average, and 110-120 high average. Possessing an average IQ is perfectly acceptable in nearly all primary school settings, since acquiring basic academic skills does not require substantial intelligence. However, when moving up to high school the impact of IQ becomes more discriminatory. Hard working students with average IQ’s will start to find that they cannot easily master certain types of information, which often creates frustration and confusion. New and/or abstract concepts, such as Geometry, Chemistry, Physics, and Honors-level math, are the typical courses which begin to confound average thinkers. Unfortunately there has been a myth that straight-A students ought to be able to study and score in the 95th percentile in all subjects, and on standardized tests –eg, ACT, SAT. The truth is that standardized tests correlate more substantially with IQ than effort and studying. I often need to educate parents about this misconception. Specifically, parents maybe dismayed when their A student scores in the range of 35% to 70% on the Iowa Basic Skills test or the SAT. The lay public does not understand that this IS the average range. Assuming a child has an average IQ, this is the normal range, even if he/she has been earning A’s in school due to effort and diligence.

Possessing higher IQ is a benefit, as is, for example, being very good-looking, or coming from a wealthy family. However, it is only ONE of many potential predictors of success. Bright people are just as plagued as others by all manner of problems, including learning disabilities or depression. When talking with families about the delicate and loaded concept of IQ, I always emphasize this fact. I also emphasize that there are at least three primary factors which predict general success:

  1. social skills (which are not measured on IQ tests)
  2. effort persistence, work habits, and determination
  3. IQ, or raw thinking ability

I have found that students with learning disabilities and Average IQ’s tend to be very hard-working and thorough –their condition has required them to be. They often have strong social skills and tenacity. To be sure, there are many wonderful and famous people who have average IQ’s, and many who have solved all manner of problems which have plagued society. So, take it all in stride, and understand the data.