What Is a Genius IQ Score?

IQ Scores & Ratings

What is a good IQ score? What is a high IQ score? What is a low IQ score?

These are common questions, particularly after someone finds out their score from an IQ test.

Lewis Terman (1916) developed the original notion of IQ and proposed this scale for classifying IQ scores:

Over 140 - Genius or near genius

120 - 140 - Very superior intelligence

110 - 119 - Superior intelligence

90 - 109 - Normal or average intelligence

80 - 89 - Dullness

70 - 79 - Borderline deficiency

Under 70 - Definite feeble-mindedness

Normal Distribution & IQ Scores


The properties of the normal distribution apply to 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

5% of people have an IQ under 70 and this is generally considered as the benchmark for "mental retardation", a condition of limited mental ability in that it produces difficulty in adapting to the demands of life.

Severity of mental retardation can be 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 IQ is generally considered to begin around 140 to 145, representing ~.25% of the population (1 in 400). Here's a rough guide:

* 115-124 - Above average (e.g., university students)

* 125-134 - Gifted (e.g., post-graduate students)

* 135-144 - Highly gifted (e.g., intellectuals)

* 145-154 - Genius (e.g., professors)

* 155-164 - Genius (e.g., Nobel Prize winners)

* 165-179 - High genius

* 180-200 - Highest genius

* >200 - "Unmeasurable genius"

More notes on High IQ and Genius IQ:

Einstein was considered to "only" have an IQ of about 160.

Mensa is a society for people with high IQ, in the top 2% (1 in 50).

In 1926, psychologist Catherine Morris Cox published a study "of the most eminent men and women" who had lived between 1450 and 1850

Source: http://wiki.answers.com/Q/What_is_considered_a_high_IQ



Normal Distribution of IQ Test Scores, a.k.a. "The Bell Curve"

Image courtesy Alessio Damato 

 Question: What Is a Genius IQ Score? 


When people talk about intelligence tests, they often discuss "genius scores" on an IQ test. What exactly constitutes a genius score on a measure of intelligence? In order to understand the score, it is important to first understand a little bit more about IQ testing in general.

Today's intelligence tests are based largely on the original test devised in the 1950's by French psychologist Alfred Binet. In order to identify students who would need extra assistance in school, the French government asked Binet to devise a test that could be used to discover which students were in need of help.

Based on his research, Binet developed the concept of mental age. Certain questions he posed were easily answered by children of certain age groups. Some children were able to answer questions that were typically answered by children of an older age - these children had a higher mental age than their actual chronological age. Binet's measure of intelligence was based on the average abilities of children of a particular age group.


Understanding IQ Scores

IQ scores generally follow what is known as the Bell Curve. In order to understand what the score on an IQ test means, there a few key terms that you should know:

Bell Curve: When IQ scores are plotted on a graph, they typically follow a bell-shaped curve. The peak of the "bell" occurs where the majority of the scores lie. The bell then slopes downward to each side-one side representing scores that are lower than the average, the other side representing scores that are above the average. An example of a bell curve can be seen in the image above.

Mean: The average score. The average is calculated by adding all of the scores together, then dividing by the total number of scores.

Standard Deviation: A measure of variability in a population. A low standard deviation means that most of the data points are very close to the same value. A high standard deviation indicates that the data points tend to be very spread out from the average. In IQ testing, the standard deviation is plus or minus 15.

A Breakdown of IQ Scores

Now that you understand these key terms, we can talk a bit more about how we interpret IQ scores. The average score on an IQ test is 100. Sixty-eight percent of IQ scores fall within one standard deviation of the mean. So that means that the majority of people have an IQ score between 85 and 115.

1 to 24 - Profound mental disability

25 to 39 - Severe mental disability

40 to 54 - Moderate mental disability

55 to 69 - Mild mental disability

70 to 84 - Borderline mental disability

85 to 114 - Average intelligence

115 to 129 - Above average; bright

130 to 144 - Moderately gifted

145 to 159 - Highly gifted

160 to 179 - Exceptionally gifted

180 and up - Profoundly gifted

Genius IQ Scores

So what is considered a genius IQ score? Generally, any score over 140 is counted as a high IQ. A score over 160 is considered by many to be a genius IQ score. Scores that are 200 and over are often referred to as "unmeasurable genius."