After a formal investigation in 1907, psychologist Oskar Pfungst demonstrated that the horse was not actually performing these mental tasks, but was watching the reaction of his human observers.
The prior research that motivated this study was done in 1911 by psychologists regarding the case of Clever Hans, a horse that gained notoriety because it was supposed to be able to read, spell, and solve math problems by using its hoof to answer.
Hans Christian Andersen | Hans Holbein the Younger | Hans Zimmer | Hans Werner Henze | Hans Memling | Hans Pfitzner | Hans Küng | Hans Conried | Hans Knappertsbusch | Hans Magnus Enzensberger | Hans-Dietrich Genscher | Hans Blix | Hans Zender | Hans Scholl | Hans Hofmann | Hans Christian Ørsted | Hans Raj Hans | Hans Habe | Hans Baldung | Baron Hans Heinrich Thyssen-Bornemisza | Hans von Ohain | Hans van Manen | Hans Urs von Balthasar | Hans Sloane | Hans Rosbaud | Hans-Georg Backhaus | Hans-Adam II, Prince of Liechtenstein | Yuvraj Hans | Hans von Halban | Hans von Bülow |
As a result of the large amount of public interest in Clever Hans, Philosopher and psychologist Carl Stumpf investigated von Osten's scientific claims.