This study tested propostions from two theories of the personal change process in sensitivity training, and investigated whether mutually perceived support relationships (MPSR) and confrontation between members of MPSRs are both necessary for personal change. The Person Description Instrument, the Support Ranking Questionnaire, the Tension Ranking Questionnaire, and the Change Ranking Questionnaire were used to gather data from four sensitivity training groups, one of which was more heterogeneous in terms of members' cognitive orientation. Two of the groups had two trainers; two others had one. The trainers varied widely in experience. These were among the findings: (1) personal change tended to correlate with the number of MPSRs; (2) low correlations in groups with two trainers suggested that support and confrontation within a trainer formed relationship are less frequent in such groups. (2) interpersonally oriented participants were perceived as supporting by both interpersonally and nonpersonally oriented participants, while participants with similar orientations tended to confront one another. (author/ly)