ABSTRACT
The missing ingredient was introduced in 1998 in an article published in the Journal of Personality and Social Psychology, which Anthony Greenwald co-authored with Debbie McGhee and Jordan Schwartz. The basic premise behind the Implicit Association Test (IAT) is that when categorising items into two sets of paired concepts, if the paired concepts are strongly associated, then participants should be able to categorise items faster into these category concepts. Greenwald introduced the new method with a thought experiment. Imagine being shown a series of male and female faces and having to respond rapidly by saying ‘hello’ to the male face and ‘goodbye’ to the female face. Then you are shown a series of names and this time you say ‘hello’ to the male name and ‘goodbye’ to the female name. Greenwald et al. (1998) reported:
In that experiment subjects gave a response on a computer keyboard with the index finger of the right hand to words that named pleasant things and to names of flowers. With the left hand they were to respond to another two categories – words that named unpleasant things and insect names. This was a very easy task. Then we made one minor change: We switched hands for the flower and insect names. Now subjects had to give the same response to pleasant words and insect names and a different response to unpleasant words and flower names. Immediately the task became hugely difficult. The slowing on a response-by-response basis was on the order of 300 milliseconds, which was a magnitude of impact nobody could have expected. We certainly did not expect it. I was the first subject in the experiment. When I experienced the slowing I found to my surprise that I could not overcome it – repeating the task did not make me faster. If I tried to go faster, I just started making errors when I was trying to give the same response to flower names and unpleasant words. This was a mind-opener.
