How is Intelligence Quotient (IQ) calculated?

The calculation of Intelligence Quotient (IQ) is traditionally done by taking a person's mental age, which reflects their intellectual capabilities, and dividing it by their chronological age, which is their actual age in years. This ratio is then multiplied by 100 to standardize the IQ score. The formula can be represented as follows: IQ = (Mental Age / Chronological Age) x 100. This method provides a comparative measure of an individual's intellectual performance relative to their age group, allowing for assessment in terms of cognitive development.

This method emphasizes the developmental aspect of intelligence, associating mental capability with age norms. It highlights how individuals perform intellectually at different stages in relation to others in their age group. The traditional understanding of IQ through this calculation helps establish a baseline for what is considered average intelligence, typically set at an IQ of 100.

The other choices do not accurately describe the standard method of calculating IQ, which is rooted in the age-related comparison of mental capabilities rather than emotional responses, mere correct answers on tests, or averaging different intelligence tests.