The Gardner’s decided to begin with that they would use a young chimp, in order to ensure that there was no ‘critical early stage’ which may affect the results of the experiment. This methodological approach into using a young chimp ensured that the studies reliability was heightened, and this also increased the validity of the experiment. Washoe was estimated to be between 8 and 14 months when she arrived. This young age of Washoe meant that little progress could be made for the first few months, and Washoe was kept in an environment, which provided minimum distractions. This close control meant that the reliability of the study was increased as it was well scientifically controlled, but also lead to questions being asked about the ecological validity of the study. Washoe life was manipulated around the study, and so a generalised theory of ability of chimpanzees would be hindered-as not all chimpanzees grow up in carefully controlled environments. This idea meant that the methodological approach of using as young chimp as possible was also questioned.
The independent variable of the study can be thought of as the training programme itself, and the dependant variable was Washoe’s actual use of the signs. Gardners’ laboratory based experiment mean that close control over the independent variable could be sustained throughout the 32 months of experimenting. The use of standardised procedures in order to teach Washoe and, to some extent, record the results meant that the study could be labelled reliable.
Records were kept about the amount of signing behaviour and number of signs used. A sign was recorded if it was reported by three different observers, as having occurred in an appropriate context and spontaneously (i.e. with no prompting other than a question such as "what is it?" or "what do you want?"). A reported frequency of at least one appropriate and spontaneous occurrence each day over a period of 15 consecutive days was taken as the criterion of acquisition. By the end of 22 months of the programme at least 30 signs met these strict criteria. These strict criteria meant that the control of the experiment was high, and this in turn meant that the reliability study was increased to some extent. Although it is questioned that the three observers may have accepted a sign to meet the criteria merely because of their close relationship with Washoe, even if it was done so subconsciously.
It is also said that Gardner and Gardner strict criteria was too strict. Many people argue that even most children would not be able to reach to the criteria set for Washoe, who was not even human. This meant that the studies ecological validity and validity in general was questioned.
The main strength of the study, which answers to the reliability of the study, was the large amount of in-depth data that the Gardners collected about Washoe’s use of sign language. The amount of research that was carried out over 32 months meant that there was little doubt over Washoe’s ability to use sign language, and so the validity was enhanced. The constant direct comparison between a chimpanzee’s ability to learn language and a human child’s ability is brought into question at this point. It can be said that however impressive the results seem, it took a very artificial based training programme in order to get Washoe to this level. This, clearly, is not how human children acquire language, so any comparison that is made is invalid. This in turn means that the validity of the study is questioned, and also that Gardners’ statement about language being unique to humans is not actually answered by the study. This shows the importance to further psychological studies, about the importance of sustaining ecological validity, as what is essential in order to eliminate doubts is the testing of a chimp learning language in a less structured, more natural context.
Although the reliability of the study is widely accepted, the validity is constantly questioned. Not all psychologists agree that Washoe did acquire language. The debate centres on the difficulty of defining language. By the end of the 32nd month, Washoe had proven that she had acquired semanticity, ability to demonstrate displacement, and was creative in words as when she combined words. But, one criterion, which is used as a demonstration of language, is structure dependence. Washoe did not always seem to care about ‘sign order.’ This lack of ability supports the argument that only humans have the innate propensity to acquire language, and that the study was merely reiterating the demand characteristics that Washoe was encouraged to perform, and so, arguably, was invalid in proving its aim.
