The effects of microswitch-based programs on indices of happiness were evaluated with 9 students who had profound multiple disabilities. Each student received an ABAB sequence in which A represented baseline phases and B, intervention phases. During the latter phases, microswitches were used to enable the students to control preferred environmental stimulation with simple/feasible responses, such as hand-pushing and foot-lifting. Results show that all students increased microswitch responding during the intervention phases. Seven of them also had significant increases in indices of happiness, whereas the other 2 did not. In an attempt to shed some light on the reasons underlying the different outcomes, we examined procedural and methodological aspects of the study.