Book T of C
Chap T of C
Ethology, the European science of animal behavior, developed out of zoology and emphasized instinctive behaviors. Tinbergen and Lorenz were two giants in the field of ethology. Tinbergen published an influential book in 1951 and followed it up with a 1952 article in Scientific American, introducing ethology to many Americans. Tinbergen described how a little fish went through a complex series of behaviors during mating season, each triggered by a specific stimulus. Species-typical behaviors are often listed in an ethogram compiled by close observation. A species-typical behavior can also be called an instinctive behavior, innate behavior, fixed action pattern, action pattern, motor program or wired-in behavior.
In 1938, Tinbergen and Lorenz collaborated on another classic article describing the egg-retrieving behavior of the greylag goose. The egg-retrieval movement shows many characteristics typical of motor programs. The behavior is stereotyped or fixed in form, it is set off by a highly specific stimulus called a sign stimulus or releaser. Once triggered, the action runs to completion (endogenous running-out). Lorenz showed that the egg-retrieval response was also triggered by supernormal stimuli : exaggerated sign stimuli which may trigger a stronger than normal response.
Lorenz pointed out two famous phenomena of animal behavior. Imprinting occurs when ground-dwelling birds follow the first object they see after hatching, usually their mother. Lorenz let baby greylag geese imprint upon him, and they followed him all around his farm. Babyishness is another pattern pointed out by Lorenz. He observed that all baby animals have a distinctive look. They have prominent foreheads, large eyes, soft jaws, fuzzy or furry bodies, and stubby limbs. This appearance seems to inspire merciful, parenting behavior in adult animals of other species, sometimes resulting in cross-species adoption.
Originally, researchers assumed that all associations were equally easy to learn. After the ethologists drew attention to the importance of evolutionary influences upon animal behavior, conditioning researchers began to recognize that some forms of learning were naturally easier than others, prepared by the animal's genetic heritage and biological makeup. Examples are Seligman's concept of prepared learning in phobias and the Garcia Effect in which food, but not sound or colored light, is associated with illness.
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Copyright © 2007 Russ Dewey