H567/03 Section B Option 1 - Intelligence and biological influences

What intelligence means

Intelligence refers to cognitive abilities that enable learning, reasoning, problem solving and effective adaptation. Wechsler's influential account emphasises purposeful action, rational thought and dealing with the environment. This is broader than memorising facts or achieving one examination grade: grades also depend on teaching, motivation and opportunity.

Psychometric psychologists infer ability from performance on standardised tasks. Scores on different cognitive tasks often correlate positively, supporting the idea of a general factor, $g$, alongside more specific abilities. A general factor summarises a pattern of differences between people; it is not a single observed organ or a complete description of every talent.

An IQ score is an operational measure of intelligence obtained from a test. Modern normed IQ scores compare performance with an appropriate reference group, normally people of the same age. A raw total of correct answers is not automatically an IQ: answering 40 items on an easy test and 40 on a difficult test need not indicate the same ability. Standardisation specifies instructions, scoring and testing conditions so that differences are more interpretable.

The definition and the measure must be distinguished. A matrix task may provide evidence about reasoning, but it cannot by itself measure all the purposeful behaviour included in a broad definition. This distinction underpins construct validity: does the test actually represent the ability it claims to measure?

Different kinds of cognitive ability

Fluid intelligence concerns reasoning about relatively unfamiliar problems, identifying relationships and working out a solution without simply recalling a learned answer. Crystallised intelligence concerns knowledge and skills accumulated through education and experience, such as vocabulary and factual understanding. They are related rather than mutually exclusive: reasoning can help a child acquire knowledge, and prior knowledge can assist a new solution.

For example, a child who infers a new rule connecting shapes shows fluid reasoning. A child who accurately explains a word learned through reading draws on crystallised knowledge. A task can involve both: understanding verbal instructions requires learned language even when the puzzle itself is unfamiliar.

This matters in a school assessment. A child learning a new language may know less of the vocabulary used by the test without having correspondingly weak non-verbal reasoning. Choosing a visual reasoning task reduces some language demands, but does not make it wholly free of learning, culture or sensory demands. A fair judgement should use suitable norms and several sources of evidence, rather than equating one unfamiliar format with low ability.

Biological influences on intelligence

The biological area examines how inherited characteristics and the nervous system contribute to cognitive functioning. Intelligence is influenced by many genetic differences, each operating within a developing organism and environment; there is no single gene that specifies a child's complete intelligence or school future. Genetic influences may affect processes involved in brain development and information processing, while learning changes the functioning of the same brain.