A team of researchers has found that after the onset of puberty, women develop wider hips than men so that their pelvis can allow the birth of large-brained babies. Until puberty, Male and female pelvis are found to be similar in width
With the onset of puberty until menopause, female sex hormone estrogen concentration reaches high levels and stabilized. High estrogen levels thus maintain high fertility and also guarantee that the female pelvis develops in most favorable form
With the onset of puberty, the male pelvis remains on the same developmental trajectory, while the female pelvis is becoming wider and reaching its full width around the age of 25-30 years. ‘This implies that the female body can modulate its pelvic dimensions ‘on demand’ and is not dependent on genetically fixed developmental programs’.
With the onset of menopause female pelvis contract again, it is assumed that a narrow pelvis is better suited to stabilizing the pelvic floor and thus to withstanding the high pressures that are generated in the abdomen during bipedal walking. As such, men and women become more similar from the age of 40 — at least as far as their pelvises are concerned.