Any parent knows that it is during a child's earliest years that one ought to be the most careful. What they eat, what they watch, even what they listen to are all factors known to have an effect on a child's development. Now, according to a new study, there is yet another factor to add to the list: where a child grows up. Anne-Claire Binter, a researcher at the Barcelona Institute for Global Health, explains the impact of city living on child cognitive health.