Behavioral avoidance tests: The effects of demand characteristics and repeated measures on two types of subjects

Abstract

Two types of subjects (undergraduates satisfying a course requirement or volunteers for a treatment program) were administered repeated Behavioral Avoidance Tests (BATs) involving a live snake. Level of demand for approach was varied by presenting the test as a measure of avoidance (Low Demand; L) or a measure of physiological reaction which required that subjects handle the target object (High demand; H). All subjects were tested twice, half under the same level of demand and half under increased or decreased demand. On BAT-I, the H condition resulted in more approach and less overt fear behavior. Treatment volunteers showed significantly less approach, more overt fear, and longer latencies to touch. The main effect of repeated testing was significant for all behavioral measures, and the Treatment × Time interaction was significant for approach and overt fear measures. Subjects displayed less fear on the second as opposed to the first BAT. The results were discussed in terms of three aspects of outcome research: demand characteristics, repeated testing effects, and type of subjects employed.