Intelligence
Intelligence questions are usually comparative or computational: calculate an IQ, or state how two theories differ. Precision in theory names earns the marks.
Definitions and theories
Binet treated intelligence as judgement and adaptation; Wechsler called it the aggregate capacity to act purposefully and deal effectively with the environment. Spearman proposed a general factor g plus specific factors s. Thurstone proposed seven primary mental abilities. Guilford's structure-of-intellect uses operations, contents and products. Cattell and Horn separated fluid from crystallised intelligence. Gardner listed multiple intelligences: linguistic, logical-mathematical, spatial, musical, bodily-kinaesthetic, interpersonal, intrapersonal, naturalistic. Sternberg's triarchic theory uses componential, experiential and contextual aspects.
Measurement
Stern's formula: IQ = (mental age / chronological age) x 100. Deviation IQ, used in the Wechsler scales, has a mean of 100 and a standard deviation of 15. Raven's Progressive Matrices is the standard non-verbal, comparatively culture-reduced test.
Worked example
A child aged 10 years 6 months has a mental age of 12 years 6 months. Convert both to months: IQ = (150 / 126) x 100 = 119. Reasoning: the two ages must be in the same unit, and the result places the child in the above-average band - but test reliability and the child's background must be considered before labelling.
Traps
Putting chronological age in the numerator; mixing years and months; presenting Gardner's list as a score-based theory; ignoring cultural bias in verbal tests; confusing fluid intelligence (reasoning, declines with age) with crystallised (knowledge, holds up).