Abstract: Inspection time (IT) is an important index of human information processing, and IT has been shown to correlate reliably with general intelligence. A common interpretation of this pattern has been that IT provides an index of a cognitive or biological substrate underpinning individual difference in IQ. The article first introduced the correlative studies between IT and IQ, discussed different theoretical explanation on the nature of correlation between IT and IQ, and then summarized the studies of the nature of correlation nature between IT and IQ from the viewpoint of biology and development. Some problems pertaining studies in this field are highlighted, and new orientation is discussed in the article

Key words: inspection time, IQ, intelligence