Epigenésis como un determinante del momento de la menarquia

Abstract

As an example of the complexity of the influence of biological and social factors over growth and developmental phenomena. we hereby present the perforrnance of fifteen somatometric variables of three groups of women between 12 and 14 years of age, each group divided into two classes, A and B, on the bas¡s of their life conditions, more or less adequated to growth. The first group, forrned by women from 144 to 155 months old, independently from any other consideration and taking into account all the var¡ables, with the exception of bicrestal diameter, upper arm muscular area and the relation upper segment x 100/lower scgnrent, showed clearly statistic differences, probably due to the different life conditions between classes A and B. In the second group, constituted by women at the moment of menarche or at most 90 days after it, this is, necesarily of the same biological age, there were no significant statist¡c diffcrences inr all somatometric values (with the exception of heigth), according to their place in class A or B, The third group, of postmenarche women from 156 to 167 months old, this is, not necessarily of the same biological age, presented differences of high statistic significance, between classes A and B, for the growth measures but not for the muscularity ones. All these demonstrates the difficulties that somatometrics interpretation can present, and which requires, in order to be carried out correctly, of an adequate knowledge of growth dynamics with regard to the participation of permittent and induction phenomena.