Abstract
980 (499 male, 481 female) members of the Dunedin Multidisciplinary Health and Development Study were asked why they decided to participate at the most recent Age-26 assessment. Verbatim responses were analysed and five categories of reasons for participation were defined: worthwhile, pleasure, compliant, inducements and coaxed. Study members who cited each reason (more than one reason could be provided) were then profiled in terms of their feelings about being a member of the study (special, positive, okay, no thoughts, negative) and their personality traits (using the ten subscales and three superfactors of the Multidimensional Personality Questionnaire) in order to help formulate strategies to ensure high participation rates in longitudinal research. The "worthwhile" group (n=410, 41.8%) participated because they thought research was important. They felt special about being a Study member and showed decisive, sociable and happy personality traits. The "pleasure" group (n=274, 28.0%) participated because they enjoyed it. They also felt special about being a Study member and were sociable. The "compliant" group (n=450, 45.9%) participated because they always had. They felt positive about being a Study member, were unstressed and had low scores on the well-being subscale. The "inducements" group (n=314, 32.0) participated because of the reimbursements. They tended to show carefree and liberal personality traits. The "coaxed" group (n=25, 2.6%) participated because they felt pestered to do so. In general, they felt negative about being a Study member. It was concluded that longitudinal researchers aiming to keep participation rates high would benefit from keeping sample members abreast of the findings so as to engender an interest in research, reimbursing sample members for their time, and making the assessments enjoyable.