A Secular Trend toward Earlier Male Sexual Maturity: Evidence from Shifting Ages of Male Young Adult Mortality

This paper shows new evidence of a steady long-term decline in age of male sexual maturity since at least the mid-eighteenth century. A method for measuring the timing of male maturity is developed based on the age at which male young adult mortality accelerates. The method is applied to mortality data from Sweden, Denmark, Norway, the United Kingdom, and Italy. The secular trend toward earlier male sexual maturity parallels the trend toward earlier menarche for females, suggesting that common environmental cues influence the speed of both males' and females' sexual maturation

Body Structure and Physical Self-Concept in Early Adolescence

In adolescence, the complexity of human ontogenesis embraces biological growth and maturation as well as mental, affective, and cognitive progress, and adaptation to the requirements of society. To accept our morphological constellation as part of our gender may prove a problem even to a child of average rate of maturation. The main purposes of the present study were to compare selected body shape factors of early adolescents belonging to different physical self-concept subgroups, and to identify those somatic factors that have the strongest influence on the physical self-concept. A randomly selected subsample of the 2nd Hungarian National Growth Study formed the sample of the analysis. Besides the anthropometric investigations, the Tennessee Self-Concept Scale was administered to altogether 2,140 adolescents (aged 11-14). The multinominal logistic regression was used to reveal the relationship between absolute body dimensions, relative body dimensions, nutritional status, body mass components, body shape, and physical self-concept. The better the physical self-concept, the less the fatness was found in both sexes. In early adolescents, having negative physical self-concept endomorphy was significantly larger than in their age-peers with good self-concept. The presumed fact that obesity is not popular in adolescence has been confirmed by this study. However, the underweight nutritional status was attractive in the girls. These results informed us about the considerable influence of the pubertal-not-normal nutritional status on the discrepancy between the ideal and actual self-concepts. </jats:p

Socioeconomic differences in childhood BMI trajectories in Belarus

10.1038/s41366-018-0042-0International Journal of Obesity4291651-166