The PNAS paper, the first to come out of the Baby’s First Years experiment, compares brain wave activity in infants in households receiving $20 per month to infants in households receiving $333 per month. Katie McLaughlin, a professor of psychology at Harvard not involved in the study who studies brain development in children, told me the PNAS paper is “maybe one of the most important papers to come out on the effects of early adversity on early development broadly, and brain development in particular.” Allyson Mackey, a professor of psychology at the University of Pennsylvania not involved in the study, agreed and argued the changes to brain wave patterns were highly significant: “My prediction is that the brain effects of cash transfer will grow as kids grow up.”