Evolutionary Influences

Learning Activities (Click on hyperlinks for activity worksheets.)

1.    Definitions

2.    Identify concepts from animal acts (Refer to Conditioned Kitties.)

3.    Provide your own examples

4.    Crossword puzzle

5.    Word search


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Evolutionary contingencies



Many of the exhibits at the IQ-Zoo and the projects of ABE were based on a knowledge of evolutionary contingencies and the careful observation of animals in their natural habitats. Evolutionary contingences refer to the factors that have shaped animal behavior over many generations, often over millions of years. The behaviors that the animals were trained to perform at the IQ Zoo were seldom new activities for them. For instance, chickens often scratch for food. Under the right circumstances, the chicken’s scratching can be made to look like dancing. Ducks dabble for food.  When dabbling over the strings of a guitar, the duck appears to be playing the instrument. However, the dancing chicken and the dabbling duck are just doing what comes naturally. 



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Instinctual Drift


Instinctual drift is the tendency of some trained animals to revert back to instinctual behaviors. In other words, they will behave in accordance with evolutionary contingencies, as opposed to the operant contingencies of their training. These behaviors are often unnecessary, and seldom useful. The term “instinctual drift” was first used by Keller and Marian Breland in their 1961 article, “The Misbehavior of Organisms,” published in the journal American Psychologist. The article addressed some deficiencies in B.F. Skinner’s book The Behavior of Organisms (1938). In his book, Skinner described the Skinner Box and the basics involved with operant conditioning. His work seemed to assert that all animals started off on equal footing when it came to operant conditioning (later, he denied that he ever implied this). However, after working with a variety of species for 25 years, the Brelands reached a different conclusion. One of the colorful examples of instinctual drift occurred when the Brelands were training animals for the “Piggy Bank” exhibit. The pigs were being trained to pick up large wooden nickels in their mouths and deposit them into piggy banks. Depositing coins was reinforced with food.  However, some of the pigs would stop picking up the coins and would instead “root” at them, shoving their snouts under the coins and tossing them into the air, as though they were digging for food. These animals had already been taught that all that they had to do to earn food was drop the coins in the bank. However, they rooted at the coins instead. Despite the fact that this behavior was completely ineffective in getting the hungry pigs their food, the pigs reverted to it, seemingly because it was what they instinctively did when they were hungry. Another example of this tendency was seen with the Capsule-Vending Chicken. The chicken was taught to pull a loop in order to deliver a plastic capsule to the customer. After the chicken triggered the delivery mechanism, a plastic capsule rolled down a slide and landed in front of the chicken. The chicken was supposed to peck at the capsule, causing it to fall off the slide and into the hands of the waiting customer. However, some of the chickens reverted to instinctive behavior and began pecking at the capsule as they would at a bean pod, with the seeming intent to break them open. To open the capsules, they would bang the capsules against hard surfaces, and often toss them into the air.