Psychological reasoning begins earlier than had been thought, study shows. Psychological reasoning begins earlier than had been thought, study shows According to conventional wisdom, babies don't begin to develop sophisticated psychological reasoning about people until they are about 4 years old. A study of 15-month-olds at the University of Illinois at Urbana-Champaign proves otherwise. The findings, published in the April 8 issue of the journal Science, potentially [...] [World of Psychology]000000comment []