Individual age changes of the morphological characteristics

Abstract

Anthropological traits are not stable during adulthood: in the sampling of a population the age is a non-negligible factor. A longitudinal study for 15 anthropological measurements in a sample of 44 adult males measured twice between 25 and 60 years at an interval of 22 years allows us to separate the influence of individual changes with age and of secular evolution in the global changes observed in transverse studies. For longitudinal body measurements, stature, sitting-height, sternal height and length of arm, the secular evolution is principally responsible for the diminution observed in transverse studies. Individual changes are observed from 45 years for the stature for instance. The diminution takes place essentially on the cervicocephalical part. For the weight, an augmentation is observed till 60 years, which is only imputed to individual changes with age. After 60 years it is not impossible that individual changes will result in a diminution of weight. Also differential selectivity is not to be excluded. For the biiliac diameter and for the upper arm circumference, the augmentation is due only to individual changes with age. As for the weight this observation is limited to the class of age 25–60 years. For the most cephalic and facial measurements the individual, changes are responsible for a global augmentation observed in transversal studies: head length and breadth, bizygomatic breadth, nose and ear height. For the lips height the global diminution is imputed only to individual changes with age.