N.N. Ladygina-Kohts earned her degree in comparative psychology at Moscow University in 1917, then became the first curator of the Darwin Museum in Moscow. Her pioneering work with the chimpanzee, Joni, was reported throughout the continent during her lifetime, earning her a series of honors in the Soviet Union. Unfortunately, Infant Chimpanzee and Human Child, her diary comparing Joni's development with that of her son, Rudy, had never been translated completely. This volume presents the first, complete English translation with 120 photographs, an introduction by Allen and Beatrix Gardner of the Center for Advanced Study at the University of Nevada and an Afterword by Lisa A. Parr, Signe Preuschoft, and Frans B. M. de Waal of the Living Links Center.