Kapp, Frysinger, Gallagher, and Hazelton (1979) have demonstrated that lesions in the amygdala can reduce certain responses commonly associated with fear (e.g., decreases in heart rate). If fear is really reduced by the lesion, it should be more difficult to train an avoidance response in those animals because the aversiveness of the stimulus will consequently be reduced. Assume two groups of rabbits: One group has lesions in the amygdala, and the other is an untreated control group. The following data represent the number of trials to learn an avoidance response for each animal.

Group with Control Lesions Group 15 9 14 4 8 10 7 6 22 6 36 4 19 5 14 9 18 9 17 15

(a) Analyze the data using the Mann–Whitney test (two-tailed).

(b) What would you conclude?