"TRICK CHIMPANZEE FULFILLS MIND TEST" wa sthe headline in a New York Times story published December 18, 1909. With subheadings such as "Dr. Witmer Declares Peter Showed Reasoning Powers Before University of Pennsylvania Clinic" and "He Might Learn To Talk", the story showed little skepticism about the amazing claims being made about Peter, a chimpanzee that had been part of the vaudeville circut for years. Billed as "a monkey with a mind", Peter had been carefully studied at the University of Pennsylvania by eminent psychologist, Lightner Witmer.
Long recognized as one of the early pioneers of American psychology, Lightner Witmer had trained under Wilhelm Wundt and James McKeen Cattell and had helped establish one of North America's first experimental psychological laboratory. Along with his other contributions to experimental psychology, Witmer had been the first to use the term "clinical psychology". He also dedicated himself to splitting off psychology from philosopy and establishing it as a separate discipline. After taking over the University of Pennsylvania's experimental psychology laboratory in 1892, Witmer became well known for his wide ranging research into child development and intelligence as well as being a pioneer in special education. He also founded the first speech clinic and developed new training methods to help children with physical and mental impairments.
Ironically, though he developed many of the tests used on children in his clinic, Witmer was extremely skeptical about intelligence tests and their increasing role in society. He argued that test results "gives us the measure of the individual's efficiency - nothing else." Witmer also rejected the tendency of society to label children idiot or feeble-minded based solely on test results rather than trying to understand the whole child. While he had his own share of prejudices (including an early bias against women in psychology which he later reconsidered), many of Witmer's ideas would be years ahead of their time.
Though his psychological laboratory had been primarily designed for studying children with learning problems, Witmer expanded his interest into the still-new field of comparative psychology. Already rejecting the hereditarian views that seemed to be the dominant trend at the time (and would become even stronger over the next few decades), Witmer became intrigued with the possibility of teaching apes to talk through careful instruction.
After his early attempts at training an infant orangutan imported from Borneo in 1909 failed, Witmer focused on a new research subject when he first saw the trained chimpanzee, Peter, performing at the Boston Keith Theater that same year. Arranging for Peter to be brought to his laboratory, Witner subjected the chimpanzee to various cognitive tests and even began trying to teach him to talk. Aided by William Furness, curator of the University of Pennsylvania Museum of Science and Arts, Witner carefully trained Peter using methods similar to what he developed for mentally impaired children.
Based on his findings, which he would publish in a 1910 article, Witmer announced that Peter had many of the same reasoning abilities seen in humans and might even learn to speak, read and write with training. That same article, "A Monkey With A Mind" would announce that Peter was "the missing link" in human evolution. To bolster his claims, Witmer trained Peter to vocalize certain sound, including the letter "P" and the word "mamma". He also brought in Dr. William Temple Hornaday, director of the Bronx Zoo, who had carried out similar studies using a trained chimpanzee named Consul (and would also become notorious for displaying a pygmy tribesman named Ota Benga in his zoo along with apes but that is another story),
Both Hornaday and Witmer insisted that chimpanzees such as Peter and Consul were more intelligent than children of the same age. In his 1910 article, Witmer went even further though. To settle fears that his testing a chimpanzee using methods designed for human might distort his results, Witmer responded:
"Peter not only has more intelligence than any animal hitherto reported in the annals of science - his intelligence is not in the class of animal intelligence as we scientists understand the term. The study of this ape's mind is a subject not fit for the animal psychologist, but for the child psychologist."
While the New York Times reported Witmer's claims with little indication of skepticism or ridicule, Witmer's fellow psychologists mostly responded with total silence. There is nothing in writing to indicate what other academics thought of this new interest but the silence may be editorial enough in his case. Though he and Furness dedicated themselves to training Peter over the next few months, Witmer still found time to remain active professionally. That included his crusade to keep experimental psychology as a pure discipline rather than bringing in spirituality and philosophy as some of his colleagues wanted. Since that meant fighting the lingering influence of William James, who was still the most popular psychologist of his time, Lightner Witmer gained more than his share of enemies as a result.
Unfortunately for Witmer, his optimism about Peter's intellect proved to be unfounded. Not only did Peter fail to learn more than some elementary skills, attempts at teaching him to speak failed as well. Though studies comparing chimpanzees to humans would become more common many years later, Witmer's efforts to compare human and chimpanzee intelligence likely discredited him in the eyes of his colleagues.
After giving up his chimpanzee research, Witmer turned to the study of criminal behaviour and put forward the radical idea that criminals were influenced more by their environment than their heredity. In a 1910 book, The Restoration of Children of the Slums, he denied the existence of "criminal instincts". He also argued that whatever defects could be seen in problem children came from their impoverished background rather than biological causes.
Ironically, Witmer also supported a 1911 bill for the forced sterilization of severely retarded males. While he rejected a purely hereditary view of intelligence, he still allowed himself to be influenced by the eugenics movement to some extent. He was never a radical supporter of eugenices though and he even took a leave of absence in 1912 to travel to Italy to study Maria Montessori's methods in training disabled children. Not long after that, he took an extended leave of absence to help the Red Cross during World War I and his career then went into a long decline. Though he was still an outspoken critic of intelligence testing and how children were being classified as a result of their test scores, Witmer stopped publishing in 1920 and largely became a forgotten figure in American psychology.
Still, by the time of his death in 1956, he managed to live long enough to see himself partially vindicated for his early primate work. He was likely unaware of Nadiya Ladygina-Kohts' work comparing chimpanzees and human children but the research project by Winthrop and Luella Kellogg with Gua the chimpanzee in the 1930s helped support some of his optimistic predictions of chimpanzee intelligence. Psychologists working with human children were also confirming many of Witmer's conclusions about the importance of environmental stimulation in developing intelligence.
In many ways, Lightner Witmer was far ahead of his time though his early support of eugenics and mandatory sterilization have darkened his reputation. Whether that along with his chimpanzee research led to his becoming so completely forgotten by modern psychologists is still open to speculation.