Shelves of evidence show the long-term, adverse consequences for an embryo of having a mother who is stressed or malnourished during pregnancy. For instance, there's medical data showing that underweight newborn babies are more at risk of heart diseases and other illnesses in adulthood.
For decades, psychologists have been trying to find out when and how children develop the ability to step outside of themselves and understand other people's minds.
A decade ago, the American Academy of Pediatrics suggested that parents limit TV consumption by children under two years of age. The recommendations were based as much on common sense as science, because studies of media consumption and infant development were themselves in their infancy.
In one of the largest studies of its kind to date, researchers have found that babies born to mothers who smoke while pregnant face substantial delays in early neurological development, and the effects may be stronger than researchers had previously thought.
In a study published online in the journal Current Biology, scientists show that neural activity in the brain gradually changes from an immature state to a more adult-like state from 35 weeks of development.