What Experiments Were Done on Alex the African Grey?

Alex was a remarkable African gray parrot who was purchased by animal psychologist Irene Pepperberg. from a Chicago pet store in 1977 when he was approximately 13 months old. Until his death in 2007 at the age of 31, Pepperberg taught Alex words that helped him vocally identify objects and differentiate quantities and colors. Pepperberg conducted hundreds of experiments to show both the intelligence of the African gray parrot and that interspecies communication might be possible.

  1. Model/Rival Training

    • Pepperberg conducted an experiment with Alex called "Model/Rival Training." Pepperberg had one human act as a trainer and another as a model. Standing in front of Alex, the trainer would hold out an object and ask a simple question about the object, such as "what color?" The human model would sometimes answer correctly and receive praise but would be scolded for inappropriate answers. According to Pepperberg, Alex was able to observe what happened when the model answered correctly or incorrectly and once the activity was understood, the bird could compete with the model for praise by answering questions correctly.

    Discrimination

    • In her 1983 paper "Cognition in the African Grey Parrot," Pepperberg described how Alex was able to "describe" simple shapes and colors to a new trainer. According to Pepperberg, when the trainer asked Alex "What color?" and "What shape?", he vocalized the correct answer approximately 80 percent of the time. "...Our subject can view an item which can be described relevantly in more than one way, decode from our question which of two categories is being targeted, and then produce, based on the question posed, the appropriate instance of that category as an answer," Pepperberg wrote.

    Similarities and Differences

    • Pepperberg stated the Alex had the ability to vocally differentiate items that had similarities and differences. To test his ability to spot similar and dissimilar items, Alex was presented with a variety of objects and asked "What's same?" and "What's different?" Pepperberg reported in a 1987 study that that Alex 's accuracy was 69.7 to 76.6 percent for pairs of familiar objects not used in training and 82.3 to 85 percent for pairs involving objects whose combination of colors, shapes and materials were unfamiliar.

    Determining Quantities

    • In her 1994 study "Numerical Competence in an African Gray Parrot," Pepperberg detailed how Alex was able to count small quantities and differentiate objects by color. In one experiment, Alex was presented with a group of four items that each consisted of two different objects and colors. If asked "How many blue?" Alex was fairly successful at vocalizing the number of blue objects presented to him, with an 83.3 percent success rating.