Is subjective age a multidimensional construct in a Japanese sample aged 20-89?

Aim: Subjective age is an emerging concept in the aging literature that predicts various aspects of quality of life, but its nature is not fully understood. This study aimed to explore whether subjective age is a unidimensional or a multidimensional construct and its relationship with quality of life through a multi-aspects approach.

Methods: We examined subjective age for 2896 Japanese adults aged 20-89 by using five subjective age measures and questions with regard to their quality of life and analyzed the results with four indexes.

Results: Factor analyses found one factor for the measures, indicating a unidimensional construct. Yet, the multi-aspect analyses revealed unique features of the measures, especially in relation to variables on the quality of life. Among the five measures, Perceived physical age is the best predictor of life satisfaction and perception of cognitive function (i.e., memory), such that the more satisfied individuals are with their life, the younger they feel. Ideal age is another best predictor in the opposite direction, such that the less satisfied individuals are with their life, the younger they want to be.

Conclusion: Although the factor analyses revealed subjective age to be a unidimensional construct, the present results also suggest the possibility that it is multidimensional in nature. In future studies, a more systematic approach is essential for a thorough exploration of scales designed to measure the multiple aspects of subjective age. This is particularly crucial in the context of predicting our well-being. Such scales could also enable us to compare the universality and individuality of subjective age across different cultures. Geriatr Gerontol Int 2024; 24: 253-258.