Evidence of growth-promoting properties of low circulating concentrations of estrogens during childhood also exists (1).Higher levels of estrogens in prepubertal girls compared with boys have been reported, which may theoretically account for the earlier onset of puberty in girls (2).A subject almost everyone will be confronted with during the teenage years – emerging romantic and sexual feelings and ‘activities' – had never previously been investigated in such a large-scale and long-term study in the Netherlands.And that was a serious knowledge gap as, of course, between the ages of 10 and 19 years young people undergo considerable physical, mental and social-relational developments that shape much of the rest of their lives!
Interestingly, the diaries the teenagers kept for the researchers reveal that the teenagers think more about falling in love and relationships than about sexual contact.
Human sex ratios, either at birth or in the population as a whole, are reported in any of four ways: the ratio of males to females, the ratio of females to males, the proportion of males, or the proportion of females.
If there are 108,000 males and 100,000 females the ratio of males to females is 1.080 and the proportion of males is 51.9%.
Girls were in breast maturity stages 2 and 3 earlier than comparable pubic hair stages.
Although breast development in girls started earlier than pubic hair development, girls completed breast and pubic hair development at approximately the same age.