A child takes an IQ test at age nine and has a mental age of 12. The child takes another IQ test at age ten and has a mental age of 14.
The early IQ tests worked out a score from mental age and real age. Use this method to calculate the change in the child's IQ score between the two tests. Show your working.
30 exam-style questions on OCR GCSE Psychology 2.1 Key Concepts, covering 2.1.1 Stages of development, 2.1.2 Brain development and the nervous system, and 2.1.3 IQ tests as a measure of intelligence. Each one has a worked solution and a mark scheme showing where the marks go.