Stress in infants and toddlers damages memory and IQ
"Researchers have found that stress in infants and toddlers does measurable damage to memory and I.Q. What investigators now call "toxic stress" can permanently changes the structure of the brain, according to reports by the American Academy of Pediatrics" (page 15).
Jeff Madrick, "The Anti-economist: Problem Number One," Harper's Magazine, 327, no. 1961 (2013), 15.