Q: Does the IQ of a person remain constant irrespective of age and other factors? What is the IQ of an average human being and what is the maximum one can have? What is the ideal age for testing IQ since there many different tests for testing it. Do all of them finally arrive at the same figure or is it likely to vary with different type of tests?

A:Intelligence is the ability to solve new problems and the term encompasses many things including abstract thinking, analogical thinking, logic, rigor, analytic sense, short-term memory, observation, spatial skills, computation skills, creativity, insight, perseverance, speed of thinking etc. The term IQ stands for ‘Intelligence Quotient’ which corresponds initially to the ratio: Mental Age divided by Chronological Age times 100. If a young boy of 10 years has an intellectual level equal to that of 12 years old, his IQ is 120 (12/10 X 100). A young girl of 8 years with the same intellectual level as the young boy has an IQ of 150 (12/8 X 100). This method of calculation (ratio) is not used in adults and for them IQ is not a ratio but a number indicating the way they distinguish themselves from the mean of the population. IQ scores indicate how intelligent an individual is i.e. in which range of the population he/she is located. For example, an engineer with an IQ of 130 is ranked #2 of a population of 100 (he reaches the top 2%). The IQ obtained by a person at two different time periods (child then adult) remains almost the same even if the way of calculating differs. The normal IQ is around 100. Persons with an IQ between 115 and 130 have a superior intelligence. People with IQ above 130 have a very superior intelligence. There are a variety of tests available to test IQ and these differ for children and adults. For children, the WISC (Weschler Intelligence Scale for Children) is used in many parts of the world while for adults there are the WAIS (Wechsler Adult Intelligence Scale) and the Stanford-Binet. All these tests include many different tasks as Vocabulary, General knowledge, Memory, Arithmetic, Puzzles, Picture completion,etc.