A recent theory states that women enter menopause at different ages and have varying extents of symptoms due in part to residence patterns after marriage--or whether couples disperse to live with paternal or maternal kin. Investigators found little support for this theory in a study of four ethnic groups in China, however. The findings are published in >Ecology and Evolution.
Sex-specific dispersal at marriage means that male and female relatedness to their residential group will vary with age, which means they may experience different evolutionary pressures over their lifespan. When looking to see if this might affect aspects of menopause, the researchers found only a small difference in menopause symptoms or age of onset between different modes of social organization, and the results were not in support of the theory.
"Actually, those women who had dispersed from their natal home seemed to experience worse menopause symptoms, which is in the opposite direction from the original theory. We wonder if the stress of living away from kin might be a contributory factor," said senior author Ruth Mace, PhD, of University College London.