Meaning of IQ Score - Part One
When a person ask what is a meaning of an IQ score, it can mean few different things: it can be what is the acronym IQ stands for, or what is the formula to calculate an IQ score, or how to relate to the number - what the score indicates, am I smart or dumb?
So as first step let us learn some history how the IQ score come about.
Way back before the term IQ exists, based on experiment that started in 1905, in 1911 a French psychologist by the name of Alfred Binet and Theodore Simon, established the concept of "mental age" (MA). This concept basically states that just as our body grows over time (chronological age = CA) , our mental ability also grows over time.
Some other experiments further proofed that the absolute difference between a person MA and his CA keep increasing over time. For example a 6 year old child has a mental age of 8 years old, when he becomes accident attorneys Minneapolis years old his mental age become 12, and become 16 when he reaches age of 12 years old. We can put it in a shortform as below:
6 ---> 8 === difference of +2 years (8-6)
9 ---> 12 === difference of +3 years (12-9)
12---> 16 === difference of +4 years (16-12)
Where the CA at the left of the arrow, and the associated MA is the number on the right of the arrow. But if you are observant enough, just as William Stern, a German psychologist had been in 1912, you will notice that the car insurance Phoenix between the CA and MA are always the same. As for the example above it has always been 4/3 i.e:
8/6 = 12/9 = 16/12 = 4/3
Further studies have shown that this ratio is actually remains constant throughout ones life - given the condition that no external environment change.
This finding of constant ratio forms the basis of Intelligent Quotient ( IQ ) score formula which is:
IQ = 100 ( MA/CA )
So if the meaning of IQ score that you want is the formula for its calculation, it is basically it just the ratio of your CA over MA then multiplied by one hundred.
For the example given above the IQ of the child is:
IQ = 100 (4/3) = 133
OK, now we know where the IQ score number come from, but a number on its own is useless.
Just like I ask you is 1 meter short or long?
To an astronomy who measuring distances of stars in light years, it is very..very short.
But to a chemist who is measuring a radius of a molecule in nanometers, it is very..very long.
Its the same to an IQ score, we have to put it into a reference so that you can actually relate a meaning to the IQ score.
The average IQ score is by definition 100.
Scores above 100 indicate a higher than average IQ and scores below 100 indicate a lower that average IQ. Theoretically, IQ scores can range any amount below or above 100, but in practice they do not meaningfully go much below 50 or above 150. Mapping of score ranges to overall population can give better picture on the meaning of IQ score.
We can put this IQ score distribution categorization and mapped it to typical employment type that fit each category:
IQ Score-----------Description---------% of Population-----------Employment Options
**********************************************************************
130+ --------------Very superior--------------2.2%-------------------Scientist,Professor
120-129 -----------Superior--------------------6.7%------------------Engineer,Manager,Executive
110-119 -----------High average--------------16.1%-----------------Teacher,Accountant
90-109 ------------Average--------------------50%-------------------Police,Machinist
80-89 -------------Low average----------------16.1%-----------------Clerk,Teller
70-79 -------------Borderline-------------------6.7%------------------Any close supervision job
Below 70 ---------Extremely low---------------2.2%
A disclaimer, I am not trying to stereotype people based on their IQ score, this merely to give a reference point on the typical society assumption. For example, Marilyn Savant, Guiness record holder for five years as the person with the highest IQ is a writer and a housewife - not a scientist or a professor.By the way, her IQ score is 228.
In the upcoming second part of this article I will cover topic such as different types of IQ tests and the shortcomings of the IQ tests.
sawahid is the owner of site http://www.dzikry.com/blog. Work professionally in software development industry, but leisurely likes to learn about human brain capacity. If you are interested to know more about human mind and thinking process check the "Brain and mind" section at http://dzikry.com/blog/category/brain-and-mind/.
posted by hoteke at 9:16 PM
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