IQ Scales! What Does the IQ Scale Measure?

What does the IQ scale measure? What is an average score? How high can an IQ be? Here are some answers to these and other questions.

IQ Scales! Average IQ ScoreAs a means of evaluation, Binet-Simon scale was found to be quite predictive correlation coefficient, between which a society mental tests and school performance estimated by the average of 0.70 (theoretical maximum is 1.00), where her credit of validity. The predictive validity of the set of attested evidence of practice was content to accept the provisional definition of intelligence test. Suite of tests, ordered by age, composition approximates intelligence operative spirit of observation, understanding, memory, reasoning, vocabulary, etc. intelligence itself representing a level of functioning of the whole composite.

Binet - Simon scale is a sample of tasks / requests as follows:

  • To discover the similarities / differences between data objects or evokes memories;
  • To name elements missing in incomplete designs;
  • To find the antonyms of words given;
  • To explain proverbs;
  • To store and reproduce material in reverse order verbally or figures;
  • To make procedural reasons (such as "if then");
  • Solve problems such as: "a dark field (circle shaped) ball was lost in the grass. We do not know any landmark, where in the jump ball, whether it went so. Having a single entry, think where to look in to find it. Indicate course with a pencil."

 IQ Scales:

  • Over 140 - Genius or almost genius
  • 120 - 140 - Very superior intelligence
  • 110 - 119 - Superior intelligence
  • 90 - 109 - Average or normal intelligence
  • 80 - 89 - Dullness
  • 70 - 79 - Borderline deficiency in intelligence
  • Under 70 - Feeble-mindedness

 Normal Distribution of IQ Scores:

  • 50% of IQ scores fall between 90 and 110
  • 70% of IQ scores fall between 85 and 115
  • 95% of IQ scores fall between 70 and 130
  • 99.5% of IQ scores fall between 60 and 140

Low IQ & Mental Retardation

An IQ under 70 is considered as "mental retardation" or limited mental ability. 5% of the population falls below 70 on an IQ test. The severity of the mental retardation is commonly broken into 4 levels:

  • 50-70 - Mild mental retardation (85%);
  • 35-50 - Moderate mental retardation (10%);
  • 20-35 - Severe mental retardation (4%);
  • IQ < 20 - Profound mental retardation (1%).

High IQ & Genius IQ

Genius or near-genius IQ is considered to start around 140 to 145. Less than 1/4 of 1 percent fall into this category. Here are some common designations on the IQ scale:

  • 115-124 - Above average
  • 125-134 – Gifted
  • 135-144 - Very gifted
  • 145-164 – Genius
  • 165-179 - High genius
  • 180-200 - Highest genius