Objective: The purpose of this study was to demonstrate the effects of the achievement motive on important variables such as the purpose in life and social participation with objective physical functions in predicting within-person fluctuations and between-person differences using longitudinal research in community-dwelling Japanese elderly people.
Methods: The final dataset consisted of 227 persons (men: 109, women: 118) from day-service centers through testing at three time points. The tests comprised a questionnaire on the achievement motive, purpose in life and so on and the measurement of physical functions. We verified the following hypothesis model; 1) achievement motive works on improvement of the purpose in life, social participation, self-efficacy, and role expectation, 2) social participation and role expectation improve the purpose in life, 3) hobbies and going out affect the purpose in life, 4) social participation and physical function affect the increase in going out, 5) achievement motive and social participation improve physical function and increase role expectation and hobbies, and 6) self-efficacy improves social participation and the purpose in life. Our hypothesized model was based on previous research and was analyzed using a multilevel structural equation modeling approach.
Results: The modified hypothesis model without hobby, grip strength, and gait speed exhibited an adequate model fit: comparative fit index = 0.904, Tucker-Lewis index = 0.775, root mean square error of approximation = 0.064, Akaike’s information criterion = 25201.17, Bayesian information criterion = 25389.59, and adjusted BIC = 25256.24. Within level, the achievement motive had significant direct effects on the purpose in life, social participation, and self-efficacy. In addition, there were significant indirect effects of the achievement motive on the purpose in life through social participation and on social participation through self-efficacy. Between level, the achievement motive had significant direct effects on all variables and significant indirect effects on the purpose in life, social participation, and going out.
Conclusion: Our findings highlight the implications of achievement motive for the purpose in life, social participation and self-efficacy of the participation at the within person and between people levels. Consequently, we understood that the achievement motive could strongly affect between-person differences more than within-person fluctuations during a short period of six months.