Der Zahlen-Verbindungs-Test and other trail-making correlates of general intelligence

Abstract

Eighty-three university undergraduates were administered Der Zahlen-Verbindungs-Test (ZVT), a trail-making test in which subjects draw lines to connect, in order, circled numbers from 1 to 90 which are positioned more or less randomly on a piece of paper, and 4 other different versions of the ZVT which were designed for this study. Subjects were required to complete each of the 5 ZVT versions in both a forwards and a backwards direction, for a total of 10 ZVT-type tests, and were also administered the Multidimensional Aptitude Battery (MAB) as a measure of general intelligence. Two other samples, each containing 30 subjects, were administered the 10 ZVT-type tests on two occasions in order to estimate their test-retest reliabilities. Scores derived from the ZVT-type tests all correlated significantly ( P < 0.01) and quite highly (as high as 0.72) with full-scale IQ scores from the MAB, and there was a trend for more complex ZVT versions to correlate more highly with IQ scores than less complex ZVT versions. The finding that a ZVT-type information-processing task, which can be administered in as little as 45 sec, accounts for as much as 50% of the variance in IQ scores provides considerable support for the notion that speed of information-processing is an integral component of general intelligence.