The winner of a decades-old debate about what scientists call the fadeout effect -- one of the most persistent research mysteries in intelligence and psychological development -- may finally have been decided.
Following a meta-analysis of experimental methods to determine whether or not the benefits of early interactions designed to raise intelligence remain over time, UC Santa Barbara postdoctoral researcher John Protzko found that the positive effects on intelligence actually diminish after a particular intervention ends. Protzko's study marks the first quantitative analysis of the fadeout effect across nearly every known intervention that has attempted to improve early intelligence.