Intelligence quotient<br><br>



  
What is intelligence? <br><br>
What is a standard deviation (SD)?<br><br>


 What is the IQ of the average person?<br><br>
The average IQ score for the normal person is supposed to be 100 (the mean) with a standard deviation of 15 (which means you can add or subtract 15 from 100).  Different IQ tests give you different scores, so defining someone strictly by score is not the best idea.  (normal iq)
 <br><br>
How high does your IQ have to be to be considered a genius?<br><br>
It varies.  An IQ score of 140+ or 145+ is the minimum to be considered a genius.
 <br><br>
Who held the highest IQ in history?<br>
What are the names of some of the main IQ Tests?<br>
What does IQ stand for?
<br>



What is intelligence? <br><br>

 The definition I like is that intelligence is "the ability to learn or understand or to deal with new or trying situations ... also : the skilled use of reason" (7)*.  I have heard some people misuse the word smart to mean knowledgeable.  That is like confusing velocity with distance.  That one can lead to the other does not mean that they are the same thing.<br><br>

What is a standard deviation (SD)? <br><br>
 Simply put, the standard deviation is a measure of the spread of the sample from the mean.  As a rule of thumb, about 2/3 of a sample is within 1 standard deviation from the mean.  About 95% of the sample will be within 2 standard deviations from the mean (3). <br><br>
 
With the standard deviation and a mean, you can calculate percentiles.  Percentiles tell you the percent of people that have a score equal to or lower than a certain score.
<br><br>

There have been various classification systems for IQ.</div>
    <div align=left>&nbsp;</div>
    <div align=left>Terman's classification was (6):</div>
    <div align=left>&nbsp;</div>
    <div align=left>
      <table cellSpacing=1 cellPadding=1 width="50%" align=center border=1>
        <tr>

          <td><strong>IQ Range</strong></td>
          <td><p align=left><strong>Classification</strong></p></td>
        </tr>
        <tr>
          <td>140 and over</td>
          <td>Genius or near genius</td>
        </tr>

        <tr>
          <td>120-140</td>
          <td>Very superior intelligence</td>
        </tr>
        <tr>
          <td>110-120</td>
          <td>Superior intelligence</td>

        </tr>
        <tr>
          <td>90-110</td>
          <td>Normal or average intelligence</td>
        </tr>
        <tr>
          <td>80-90</td>

          <td>Dullness</td>
        </tr>
        <tr>
          <td>70-80</td>
          <td>Borderline deficiency</td>
        </tr>
        <tr>

          <td>Below 70</td>
          <td>Definite feeble-mindedness</td>
        </tr>
      </table>
    </div>
    <div align=left>&nbsp;</div>
    <div align=left>(Terman wrote the Stanford-Binet test (1), which has a SD of 16.) </div>

    <div align=left>&nbsp;</div>
    <div align=left>Later, Wechsler thought that it would be much more legitimate to base 
      his classifications on the Probable Error (PE) so his classification was 
      (6):</div>
    <div align=left>&nbsp;</div>
    <div align=left>
      <table cellSpacing=1 cellPadding=1 width="50%" align=center border=1>
        <tr>
          <td><strong>Classification</strong> </td>

          <td><strong>IQ Limits</strong></td>
          <td><strong>Percent Included</strong> </td>
        </tr>
        <tr>
          <td>Very Superior</td>
          <td>128 and over</td>

          <td>2.2</td>
        </tr>
        <tr>
          <td>Superior</td>
          <td>120-127</td>
          <td>6.7</td>
        </tr>

        <tr>
          <td>Bright Normal</td>
          <td>111-119</td>
          <td>16.1</td>
        </tr>
        <tr>
          <td>Average</td>

          <td>91-110</td>
          <td>50</td>
        </tr>
        <tr>
          <td>Dull Normal</td>
          <td>80-90</td>
          <td>16.1</td>

        </tr>
        <tr>
          <td>Borderline</td>
          <td>66-79</td>
          <td>6.7</td>
        </tr>
        <tr>

          <td>Defective</td>
          <td>65 and below</td>
          <td>2.2</td>
        </tr>
      </table>
    </div>
    <p>Mental deficiency used to be more finely classified using 
      the following technical terms that&nbsp;later began to be abused&nbsp;by the 
      rest of society (5):</p>

    <p>
    <table cellSpacing=1 cellPadding=1 width="35%" align=center border=1>
      <tr>
        <td><strong>IQ Range</strong></td>
        <td><strong>Classification</strong></td>
      </tr>
      <tr>
        <td>70-80</td>

        <td>Borderline deficiency</td>
      </tr>
      <tr>
        <td>50-69</td>
        <td>Moron</td>
      </tr>
      <tr>

        <td>20-49</td>
        <td>Imbecile</td>
      </tr>
      <tr>
        <td>below 20</td>
        <td>Idiot</td>
      </tr>

    </table>
	<p>
    These are now largely obsolete and mental deficiency 
is now generally called mental retardation.&nbsp; The following is the 
currently used classification of retardation in the USA (5):
</p>
<p>
<table cellSpacing=1 cellPadding=1 width="35%" align=center border=1>
  <tr>
    <td><strong>IQ Range</strong></td>
    <td><strong>Classification</strong></td>

  </tr>
  <tr>
    <td>50-69</td>
    <td>Mild</td>
  </tr>
  <tr>
    <td>35-49</td>

    <td>Moderate</td>
  </tr>
  <tr>
    <td>20-34</td>
    <td>Severe</td>
  </tr>
  <tr>

    <td>below 20</td>
    <td>Profound</td>
  </tr>
</table>