After graduating from university, McQueen went to the University of London where he studied both general and experimental psychology, taking out a first class honours degree in science. He continued his research in psychology at the Psychological Laboratory of University College London, specialising in testing and measurement, where he was supervised by Professor Charles Spearman, one of the early psychometricians. McQueen focused his work on the "Distribution of Attention" in individuals, rejecting earlier claims that there were certain individuals types who possessed general powers of an extensive attention span capable of taking on a number of tasks at the same time. The result of this study was published in the British Journal of Psychology as a monograph supplement in 1917.