Real studies, summarized and simplified for practice. These are not the sources on Friday's test.
Source A: Garcia & Koelling (1966)
Introduction: Researchers asked whether rats can link any cue with any consequence equally well.
Participants: Laboratory rats.
Method: Rats drank sweet-flavored water. Every time they licked the spout, a light flashed and a click sounded, so the water came with a taste, a sight, and a sound. Afterward, one group was made sick to their stomachs. A second group got a mild shock to the feet instead. Later, the researchers offered each rat either sweet water with no light or click, or plain water with the light and click.
Results: Rats that were made sick avoided the sweet taste but not the light and click. Rats that were shocked avoided the light and click but not the sweet taste.
Discussion: Rats are prepared to link taste with illness, and sights and sounds with outside pain, much more easily than the other way around.
Source B: Cook & Mineka (1989)
Introduction: Researchers asked whether monkeys can learn a fear of anything by watching another monkey's fear, or learn some fears more easily than others.
Participants: Rhesus monkeys raised in a lab, which had never seen snakes and showed no fear of them.
Method: Each monkey watched videos of another monkey reacting with fear. The videos were edited so that the monkey on screen seemed afraid either of toy snakes and toy crocodiles, or of flowers and a toy rabbit. Afterward, the researchers tested whether the watching monkeys would reach past each object to get a treat.
Results: Monkeys that watched fear of toy snakes or crocodiles became afraid of those objects and avoided reaching past them. Monkeys that watched the same fear reactions to flowers or a toy rabbit did not become afraid of them.
Discussion: Monkeys learn fear by watching, but only for some objects. They seem prepared to learn fear of animals that were dangerous to their ancestors.
Source C: Breland & Breland (1961)
Introduction: Two animal trainers, former students of B. F. Skinner, reported problems they ran into training animals for shows and ads with operant conditioning.
Participants: Pigs and other animals trained with food rewards.
Method: Pigs were trained, with food rewards, to pick up large wooden coins and drop them into a piggy bank across the room.
Results: The pigs learned quickly. Over several weeks, though, they began dropping the coins, pushing them along the ground with their snouts, and tossing them in the air. They took longer and longer to finish, which delayed their food, even though rooting earned them nothing.
Discussion: The pigs drifted back toward natural food-finding behavior (rooting) that got in the way of what they had been reinforced to do.