[[Wolfgang Köhler|Wolfgang Köhler's]] pioneering research on the intelligence of apes is a classic example of research in this area. Stanley Coren's book, ''[[The Intelligence of Dogs]]'' is a notable popular book on the topic. | [[Wolfgang Köhler|Wolfgang Köhler's]] pioneering research on the intelligence of apes is a classic example of research in this area. Stanley Coren's book, ''[[The Intelligence of Dogs]]'' is a notable popular book on the topic. |