Human females are only joined by a handful of other animals, including a few long-lived whale species, which have a long life phase when reproduction ends and the time is right to mingle with the young. -children. This freehand (or all-finned) approach to securing your genetic heritage is apparently paying dividends. An analysis of Finnish pre-industrial records in 2019 suggested that the presence of a maternal grandmother aged 50 to 75 made a given grandchild 30% more likely to survive infancy than a child whose grandmother maternal mother was deceased. An analysis of 45 historical and contemporary populations showed that the presence of maternal grandmothers can increase child survival rates even more than the presence of biological fathers. Similarly, orcish grannies are the same, scientists recently reported in the Proceedings of the National Academy of Sciences, with postmenopausal females dramatically increasing the chances of their calves’ survival.
Maybe these fat graying girls are wise in the way of great white shark attacks and other high seas childcare hacks. In the human case, grandmothers most likely also protect physical health and mental health of their daughters, which in turn can help boost a baby’s chances of survival. (Orcas, on the other hand, seem more essential to their sons in their 30s, according to a 2012 report from the journal Science.)
Human maternal behavior is not only genetically predestined, but also very sensitive to the social environment of the woman. And while new human mothers around the world are renowned for our strength and adaptability, maternal grandmothers are the rare global constant in our lives, said two anthropologists, Brooke Scelza and Katie Hinde, in a fascinating 2019 article. from the journal Human Nature.
Indeed, in the United States, where single mothers are leading households in record numbers, Grandma – or Mamie, Yaya, Nanny, Me-maw or Foxy – is perhaps more important than ever. This innocent-looking old lady, Drs. Scelza and Hinde claim, is a new mother’s secret weapon, and often her most crucial source of “social support” – an emotional buffer with physiological weight.
Regardless of their socioeconomic position, women who feel socially supported are less stressed during pregnancy, according to a small but striking 2019 study by researchers at Columbia University and NewYork-Presbyterian, and psychological stress severe is linked to birth complications. Women with the support of their own parents have lower rates of postpartum depression, possibly mediated by a more gradual increase in late pregnancy in a chemical called placental corticotropin-releasing hormone, a team found. from UCLA.
Moms’ daughters can also have easier births, fewer Caesarean sections, and more robustness newborns who settle more easily into the daily routine. Supported mothers also report being less tired after childbirth and having better breastfeeding outcomes.
(Strangely enough, emotionally supported mothers may also be more likely to have grandsons: the Columbia-New York-Presbyterian study suggests that less stressed women are more likely to give birth to boys, probably because men are notoriously vulnerable to stress-related miscarriages.)