I’ve mentioned before that I was lucky enough to work with Alex the African gray parrot when I was an undergraduate. As you might imagine, I can tell lots of interesting stories about that time, but the following is my favorite. It’s such a great example of how our expectations can cloud our judgment.

The summer that I worked in Irene Pepperberg‘s lab, I ran an project modeled after speech-acquisition experiments done with young children. Scientists (often a parent or friend of a parent) recorded the child’s speech during the day and then again when they were alone in their crib at night. They discovered that children often practice new sounds, words, and phrases when they are alone before saying them in public. One researcher referred to these night-time monologues as “crib-talk,” so we dubbed our project “cage-talk.”

Using a voice-activated microphone and a tape recorder (this was high-tech for the late 80s), I collected hours of Alex’s night time mutterings. We made our recordings in the summer time, when there was lots of daylight in the lab after the workday ended. Left alone for the night, Alex would climb around on his cage and talk to himself before settling down to sleep.

Later, I would transcribe the tapes, writing down any of the sounds, syllables, or words recorded. One time, when I was transcribing tapes in our apartment living room, my housemate Paul came in and stood listening as I played the tape.

After a few minutes, he asked me, “Which one is the bird?”

I laughed. All of the voices were Alex.

Paul’s confusion wasn’t surprising. Most of what Alex said sounded very human. He spoke in several accents that he’d picked up from his different trainers over the years, but each word was always pronounced in the same way. His most noticeable accent was Bostonian. He pronounced “shower” without the r (“show-ah”).

Some words he said in Irene’s voice, some like some other trainer he was working with when he learned the word. But some pronunciations were all his own, like his dramatic way of saying key: “kuh-eeee.”

My favorite was the strange way he said “blue,” one of the words I helped him learn. He had a very hard time making the initial b-sound (you really need lips for this). We said “blue,” and he said “ooo.”

We all began to emphasize the b by repeating it, and to our dismay, he suddenly got it. After that, whenever you showed him a blue object and asked him “What color?”, he said quite clearly, “buh-buh-buh-blue.” He was an excellent if a somewhat literal-minded student.

I’m not sure why Paul was confused. Did he think a parrot could only make the repetitive squawks of a Hollywood pirate’s macaw? Did the various different accents make him think that there had to be more than one speaker? Or was he simply assuming that because humans trained him, some of the words he heard on the tape must be spoken by someone other than Alex?

Whatever the reason for his bewilderment, Paul clearly had expectations that led to his mistake. When we think we know what’s going on, we make assumptions. Assumptions can get us in trouble and result in false conclusions, like listening to bunch of parrot talk and thinking at least some of it must actually be people speaking.

Have you gotten caught assuming something that was wrong?