Overview

• Luella and Winthrop Niles Kellogg raised their 10‑month‑old son, Donald, alongside a chimpanzee named Gua from June 26, 1931, until March 28, 1932 to examine environmental influence on behavior.
• The pair were treated as siblings under constant observation with harsh tests reported, including chair spinning, gunshots to measure startle reactions, and spoon strikes to the skull.
• The study concluded after nine months with Gua returned to the Orange Park primate colony, as contemporaneous commentary cited fatigue, book preparation, Gua’s growing strength, and safety worries.
• Winthrop later published The Ape and the Child, and reports note Donald exhibited chimp‑like behaviors during the study and died by suicide decades later at age 43.
• Today’s retrospectives emphasize the ethical failings and human–animal consequences, also noting Gua died of pneumonia about a year later at roughly age three.