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.

Genetic and environmental relationships between head circumference growth in the first year of life and sociocognitive development in the second year: a longitudinal twin study.

Although growth in head circumference (HC) during infancy is known to predict later childhood outcomes, the mechanisms underlying this association with later sociocognitive abilities remain undetermined. Thus, using a sample of 241 pairs of normally developing Japanese twins, this study investigated the underpinnings of the association between HC growth (difference between HC at birth and at 10 months) and sociocognitive abilities at 19 months as measured by 10 items from the M-CHAT. Phenotypic correlations between HC at birth and sociocognitive abilities and between HC growth and sociocognitive abilities were marginal and not significant. However, multivariate genetic analyses using Cholesky decomposition revealed that genetic influences on HC growth and those on sociocognitive abilities were negatively associated. On the other hand, shared and nonshared environmental influences on HC growth were positively associated with influences on sociocognitive abilities. Genetic and environmental influences on HC at birth were not significantly associated with influences on sociocognitive abilities. These results help to clarify the role of brain growth during infancy in the subsequent development of sociocognitive abilities and highlight the importance of examining the different roles of genetic and environmental influences in studies of these areas.

Reliability and validity of a short Japanese version of the UPPS-P Impulsive Behavior Scale.

OBJECTIVE: This study aimed to verify the reliability and validity of a Japanese version of the S-UPPS-P Impulsive Behavior Scale. This is expected to facilitate comparisons of findings between international and Japanese samples in studies of impulsivity. METHODS: Two surveys were conducted. In the first survey, 632 participants, aged 20-44 years old, completed a translated version of the Japanese S-UPPS-P Impulsive Behavior Scale, the Motor Impulsiveness Scale, a short form of the Big-Five scale, the short Grit scale, and the brief version of the self-control scale. Two weeks later, the second survey containing the S-UPPS-P and the motor impulsiveness scale were completed by 450 participants who had completed the first survey to examine test-retest reliability. RESULTS: In the first survey, an exploratory factor analysis was performed on the S-UPPS-P responses. A four-factor solution was the most suitable solution, with the factors of "Lack of Perseverance," "Lack of Premeditation," "Sensation Seeking," and "Negative-Positive Urgency." Then, a confirmatory factor analysis was performed. The conformity index of the original five-factor model was slightly better than that of the four-factor model. We also compared the five-factor model's conformity index with three other models that had been examined in the original and other foreign language versions of the S-UPPS-P. The five-interrelated factor model had the best model fit. The reliability of the five scales was confirmed. The scales exhibited internal consistency with α coefficients ranging from 0.65 to 0.79, in addition to the test-retest reliability ranging from 0.74 to 0.80. The convergent validity of each S-UPPS-P scale was supported by high relationships with the four personality scales, with the highest correlation coefficients ranging from 0.37 to -0.67. CONCLUSION: The reliability and validity of the Japanese version of the S-UPPS-P were confirmed, despite the minor limitations of the exploratory factor analysis providing a four-factor solution instead of a five-factor solution, and the α reliability coefficients of two scales being acceptable but rather low. Thus, comparisons of findings between international and Japanese studies on impulsivity could be facilitated.

Preschool children's eating and sleeping habits: late rising and brunch on weekends is related to several physical and mental symptoms.

OBJECTIVE: As the relationships of sleep-wake schedule and mealtime with children's behaviors have not often been studied together, we investigated the relationships of these lifestyles variables with preschool children's well-being. METHODS: Using a network survey, we investigated several lifestyle variables of 1000 families with preschool children. RESULTS: Our previous articles reported that preschool children's bedtime was delayed by the compulsory nap routine in Japanese nursery schools. The present study revealed similar results. We conducted a cluster analysis with children's meal and sleep time data, which yielded five different lifestyle groups. Cluster 1 was characterized by "extremely late and irregular" meal and sleep times; similar to Cluster 1, Cluster 2 was a "late and irregular" lifestyle group. Cluster 3 was a "mildly late" lifestyle group. Cluster 4 was an "early bird and regular lifestyle" group, and Cluster 5 resembled the "early bird and regular lifestyle" group on weekdays, but was "late and irregular on weekends." It was found that the later and more irregular the children's meal and sleep times, the worse their physical and mental condition. Even for Cluster 5, the children who had early and regular meal and sleep times on weekdays, getting up and having breakfast late and irregularly on weekends showed worse physical and mental conditions. These problematic symptoms observed in children with late meal and sleep times on weekends might be partly associated with the irregularity of their habits and partly associated with delayed mealtime, especially for breakfast (brunch). CONCLUSION: A stable lifestyle, including a regular sleep and wake schedule and mealtime, is important for preschool children's mental and physical health.

[Graphical modeling for constructs: an integrated solution for factor analysis and GM].

This research develops a new method for analyzing relation for factors which combines graphical modeling (GM) and factor analysis. In this method, estimation of the inverse of the variance-covariance matrix is done in the framework of factor analysis, and then the data-model fit is investigated using GM. The partial correlation coefficients of the estimated model are calculated, and the estimation of parameters is repeated until discovery of the worst fit index. In order to confirm the effectiveness of this method, three correlation matrices were analyzed as a real data study. In first and second case, intelligence models of Harman and Turstone were restructured using this method. In third case, EQ model was structured using it. The results show that this method can be apply GM for latent variables and a good assistant to set up path models for factors.

[The ranking model which estimates the factor scores of residual variables].

In this research, a new directions for utilizing the residual variable score in structural equation modeling was proposed. The residual variable score is created by removing the influence of the comprehensive index, which is strongly related to brand cognition from each trait factor. By using it as a new index, we tried to detect low cognition and high evaluation Brands which are not ranked high in the comprehensive index. It was shown that the ranking by the residual variable score on the same trait has very high correlation between years and same trait, and low correlation with the comprehensive index. Thus, the discriminant validity and stability of the new index were identified. Concerning the interpretation of the new index, it became clear that the brand which shows an increasing trend with the new index has the uniformly low degree of cognition as compared with the descending brand. It indicates that the new index has the capability of detecting brands with low cognition and high evaluation Brand.