Happy Mother's Day! Science has told us all sorts of fascinating things about the uniquely intimate link between mother and child at the biological level. Want to learn more? Read the full story: http://www.vox.com/2014/5/10/5699674/6-remarkable-things-science-has-taught-us-about-mothers
  1. Babies begin listening to their mothers' speech in the womb
    In 2013, scientists conducted an interesting study with 80 newborns in Tacoma, Washington and Stockholm, Sweden: they played them sounds in English, Swedish, or other languages. The scientists wanted to see if the babies would be more interested in noises in languages other than their mothers'. As it turns out, they did — the newborns could control how long the sounds played by sucking on a pacifier, and they consistently sucked more for sounds in languages other than their own.
  2. A mother's saliva might be good for a baby's health
    For years, some mothers whose babies dropped their pacifiers on the ground might pick it up, suck it clean, and pop it back in the infant's mouth. Experts widely recommended against doing this. But this year, Swedish researchers came to an unexpected finding about this seemingly gross habit — parents who do it have kids with significantly lower rates of allergies, eczema, asthma, and other auto-immune diseases.
  3. Breast milk confers all sorts of immune system benefits — and may even protect against HIV
    Breast milk is widely known to provide all sorts of nutritional benefits that can't be matched by formula. One of these is the boost it gives to a baby's immune system: because of the antibodies that are transmitted through a mother's milk, breastfed babies are more resistant to infections of the respiratory system and digestive tract during early childhood. But recently, scientists have discovered that breast milk can protect against a very different sort of infection: HIV.
  4. For premature babies, skin-to-skin contact with a mother improves health
    Having a mother hold a premature baby closely against her chest for at least a few hrs/day — kangaroo care — is practiced at an increasing number of hospital neonatal care units. Research shows that it provides all sorts of health benefits to newborns. Compared to strictly keeping premature babies in incubators, studies have found that daily kangaroo care can help them gain weight faster, be more resistant to infections and hypothermia, and experience less pain during uncomfortable procedures.
  5. A mother's brain may contain cells from her children
    During pregnancy, the placenta links the mother and fetus, allowing nutrients to flow from mother to fetus and waste to move in the opposite direction. The organ is built from cells from both of them, and the cells can migrate through it, ending up and multiplying in the other's body. About 50% of mothers have their children's cells inside them — most often embedded in her skin and in organs like her lungs, liver, and kidneys. A mother's cells can also end up in her child, although less common.
  6. The word "mother" might date to the end of the Ice Age
    Linguists analyzed cognates shared by a big range of different language families, including Uralic, Dravidian, and Inuit-Yupik. By mapping the words' relationships and using what we already know about the rates at which languages mutate over time, they found that there are at least 23 "ultraconserved words" that are shared between all these languages because they've changed relatively little since about 15,000 years ago.