In the field of behavioural sciences, the Mann‐Whitney U
test is one of the most commonly used non‐parametric statistical tests (Kasuya, 2001). This test was independently
worked out by Mann and Whitney (1947) and Wilcoxon
(1945). This method is thus often called the Wilcoxon‐Mann‐
Whitney test or the Wilcoxon sum of ranks test.