Question

Read the case and answer the question that follows.

Alfred Binet, in 1905, was requested by the French government to devise a method by which students who experienced difficulty in school could be identified. Binet and his colleague, Theodore Simon, began developing questions that focused on areas not explicitly taught in schools those days, such as memory, and attention skills related to problem-solving. Using these questions, Binet determined which were ones that served as the best predictors of school success. Binet quickly realized that some children were able to answer more advanced questions than older children were generally able to answer and vice versa. Based on this observation, Binet suggested the concept of mental age, or a measure of intelligence based on the average abilities of children of a certain age group. This first intelligence test is referred to as the Binet-Simon Scale. He insisted that intelligence is influenced by many factors, it changes over time, and it can only be compared in children with similar backgrounds.

‘Binet quickly realized that some children were able to answer more advanced questions than older children were generally able to answer and vice versa’. Why do individuals differ in intelligence? Using examples, give reasons for your answer.

Answer 1

Intelligence: Intelligence is a product of both nature and nurture. The interplay of Nature and Nurture The evidence for hereditary influences on intelligence comes mainly from studies on twins and adopted children. The intelligence of identical twins reared together correlates by almost 0.90. Twins separated early in childhood also show considerable similarity in their intellectual, personality, and behavioural characteristics. The intelligence of identical twins reared in different environments correlated to 0.72, those of fraternal twins reared together correlate with almost 0.60, and those of brothers and sisters reared together correlated with about 0.50, while siblings reared apart correlate with about 0.25. Another line of evidence comes from the studies of adopted children, which show that children’s intelligence is more similar to their biological rather than adoptive parents.

With respect to the role of environment, studies have reported that as children grow in age, their intelligence level tends to move closer to that of their adoptive parents. Children from disadvantaged homes adopted into families with higher socioeconomic status exhibit a large increase in their intelligence scores. There is evidence that environmental deprivation lowers intelligence while rich nutrition, good family background, and quality schooling increase intelligence. There is a general consensus among psychologists that intelligence is a product of the complex interaction of heredity (nature) and environment (nurture). Heredity can best be viewed as something that sets a range within which an individual’s development is actually shaped by the support and opportunities of the environment.