“…Villiers, 1977), and opportunities to view sexually interesting slides (Cliffe & Parry, 1980). Extensive reviews of the literature leave no doubt that matching theory provides an excellent description of behavior on concurrent schedules (Baum, 1974(Baum, , 1979de Villiers, 1977;Wearden & Burgess, 1982 (Bradshaw, Szabadi, & Bevan, 1976, 1977, 1978McDowell & Wood, 1984, 1985 subjects. For (de Villiers, 1977;Rachlin & Baum, 1972) and human (Bradshaw, Szabadi, & Bevan, 1976) subjects has confirmed this interpretation of re.…”