their score depended on the time and smoothness of the solution. The mirror-tracing situation was the stressful situation, and the normal tracing was the non-stressful, control situation. Experimenters observed that the mirror-tracing task caused more drawing outside the boundaries, increased overt signs of stress and anxiety, and required more time to accurately complete. The mirror-tracing situation produced 89% Einstellung solution on the first two criticals instead of the 71% observed for normal tracing. In addition, 55% of the subjects failed with the mirror while only 18% failed without the mirror. Hidden-word test for stutterers In 1951, Solomon gave both stutterers and fluent-speakers a hidden-word test, an arithmetical test, and a mirror-maze test. Experimenters called the hidden-word test a “speech test” to increase stutterer anxiety. There were no marked differences between the stutterers and the fluent-speakers for the arithmetical and mirror-maze tests. However, the results reveal a significant difference between the performance of the stutterers and the fluent-speakers on the "speech test." On the first two critical problems, 58 percent of the stutterers gave Einstellung solutions whereas only 4 percent of the fluent speakers showed Einstellung effects. Age The original Luchins and Luchins experiment tested nine-, ten-, eleven-, and twelve-year-olds for the Einstellung effect. The older groups showed more Einstellung effects than the younger groups in general. However, this initial study did not control for differences in educational level and intelligence. To remedy this problem, Ross (1952) conducted a study on middle-aged (mean 37.3 years) and older adults (mean 60.8 years). The adults were grouped according to the I.Q., years of schooling, and occupation. Ross administered five Einstellung tests including the arithmetical (water jar) test, the maze test, the hidden-word test, and two other tests. For every test, the middle-aged group performed better than the older group. For example, 65% of the older adults failed the extinction task of the arithmetical test, whereas only 29% of the middle-aged adults failed the extinction problem. Luchins devised another experiment to determine the difference between Einstellung effects in children and in adults. In this study, 140 fifth-graders (mean 10.5 years) were compared to 79 college students (mean 21 years) and 21 adults (mean 43 years). Einstellung effects prior to the extinction task increased with age: the observed Einstellung effects for the extinction task were 56, 68, and 69 percent for young adults, children, and older adults respectively. This implies that there exists a curvilinear