account of the Clever Hans conference (1(6):355-359, 1980). As I was not present I cannot comment on the manners of the participants, but as the editor of a hu-mane magazine to which Dr. Thomas Se-beok frequently contributes, I would like to make a few observations on the matter. It appears

In the first decade of the 20th century, a horse named Hans drew worldwide attention in Berlin as the first and most famous “speaking ” and thinking animal. Hans solved calculations by tapping numbers or letters with his hoof in order to answer questions. Later on, it turned out that the horse

used a standard two-way object-choice task to focus on this potential Clever Hans effect. We investigated if and how owners ’ knowledge and beliefs influenced their dogs ’ performance. In two experiments, as is typical in such pointing tasks, the owners sat behind their dogs, in close auditory

were used for each task. RT was slower for task repetition than for cue repetition and about the same as RT for task alternation, consistent with Model 2 but not Model 1. The results suggest that the explicit task-cuing procedure does not require an endogenous act of control. Clever Hans was a

and attribute them to agents outside themselves. This was the case in 1904 when trainer Wilhelm von Osten exhibited Clever Hans, a horse who appeared to answer questions correctly by tapping a hoof. Extended investigation revealed, however, that Hans was only clever enough to respond to an unconscious movement

called ‘‘Clever Hans’ ’ has just been examined by a special commission of experts, in order that a decision might be arrivedAQ1 at whether it is a horse possessed of extraordinary brain power... —From The London Standard, in The New York

Full list of author information is available at the end of the article three times faster compared to their murine counterparts [12]. In the chimeric mice of Han and colleagues [12], theinformation and communication [1]. Accordingly, their

, the role that participants ’ knowledge of the study’s purpose or hypotheses may play in influencing the outcome has preoccupied researchers since the very early days of scientific psychology.1 On the other hand, as the (in)famous case of Clever Hans (Despret, 2004; Pfungst, 1911/1965) so strikingly

/herself – might be biased because they understand the hypotheses. When faced with complex materials, they could then use these hypotheses to arrive at the judgment. 3. Observer–expectancy effects (the ‘‘clever Hans’ ’ effect): indivi-duals that the researcher asks to provide a judgment could be biased because

DNA in a sequence-specific mannerHans Clevers2 and Olaf Nielsen1,3 and some of them are activators of transcription. Members