Inspection time and IQ in young children

Three studies investigating the relationship between IQ, mental age (MA), chronological age (CA) and inspection time (IT) are reported. Forty-seven children participated: three age groups, 6, 8 and 10 yr, attending a London primary school and with IQs ranging from 75 to 141. The IT task was incorporated into a microcomputer-controlled video game and two measures of IT were obtained from two psychophysical procedures: method of limits and method of constant stimuli. All three studies found that a significant relationship was maintained for Ss over the full age range. Although, in general, IT decreased with increasing CA, bright 6-yr-olds had similar ITs to dull 10-yr-olds. Given that the latter have higher MA than the former and they have had more years experience of school, it is concluded that the IT/IQ relationship is primarily based on fundamental aspects of information processing, such as processing speed, rather than on task sophistication. The two psychophysical procedures produced different estimates of IT. However, it is concluded that using two methods can reduce the noisy effects of variability in responding of children. Reliabilities in the order of r = 0.45 are reported for the task.