Breastfeeding may be linked with better performance on cognitive tests. In a small 2016 study, researchers monitored daily breast milk and formula given to 180 babies for their first 28 days of life. At 7 years old, children who consumed breast milk performed better on cognitive tests they were given.
Junk food diets for kids under three may be linked to lower scores on an intelligence test. Children who ate processed junk foods before the age of three were shown to have a lower score on the Wechsler Intelligence Scale for Children than their peers by the time they were eight years old. A diet rich in vitamins and minerals was shown to do the opposite.
Poverty may be linked with poorer performance on cognitive tests.A small 2013 study at Princeton found that “a person’s cognitive function is diminished by the constant and all-consuming effort of coping with the immediate effects of having little money, such as scrounging to pay bills and cut costs.”
There may be a link between intelligence and life expectancy.Multiple studies around the world have shown a link between intelligence (as measured by cognitive tests) and mortality. There is even a field of study called cognitive epidemiology dedicated to the relationship. Still, it’s not been entirely proven why this link exists.
Intelligence and social skills may be linked. “Intelligence, to a large extent, does depend on basic cognitive abilities, like attention and perception and memory and language,” Aron Barbey, a neuroscientist at the University of Illinois and coauthor of the study, told Scientific American. “But it also depends on interacting with other people,” he continued.