When both chronological and mental age of Poonam is 9 years, her intelligence category may be considered as

Intelligence Quotient is commonly known as IQ refers to the score of a standardized test that assesses and measures human intelligence.

• The first test to measure intelligence was developed by Binet and Simon in 1905. 
• Terman in 1916 revised the test and devised the concept of Intelligence Quotient.

Key Points

• An individual’s Intelligence Quotient (IQ) is determined by the formula given below,

\({\bf{Intelligence}}\;{\bf{Quotient}}\;\left( {{\bf{IQ}}} \right) = \frac{{{\bf{Mental}}\;{\bf{Age}}\;\left( {{\bf{MA}}} \right)\;}}{{{\bf{Chronological}}\;{\bf{Age}}\;\left( {{\bf{CA}}} \right)}} \times 100\)

• Where, Mental Age is based on intellectual development.
• Chronological Age is the number of years a person has lived.
• When a person’s mental age is equal to his chronological age, she/he is said to have a normal/average IQ.
• If an individual's IQ lies in the 90-109 range, it means his/her IQ is normal/average.
• For example, if the mental age and chronological age of Poonam are 9 and 9 respectively., then her IQ would be 9/9 x 100 = 100.

Additional Information

The below table shows classification of IQ: