Biological Basis of Social Development

• Darwin wrote a book that tried to show the relationship between the emotions of animals and that of man; “The emotions of man and animals”.

• Question; “What is the purpose of social behavior”

Three Perspectives on Animal Behavior

• We have studied two of these methods: The physiological perspective and the behavioral perspective

The Zoological Perspective

• Ethology is a natural science, a branch of biology, from which it took the comparative method for the study of behavioral morphology and the analytic method for the causal analysis of behavioral physiology. Its philosophical base is a critical realism. Its orientation is neo-Darwinistic and it enjoys a fruitful exchange of ideas with other schools of behavior……Eibl-Eibesfeldt.

Fixed Action Patterns of Behavior

• 1) FAPs are regarded as stereotyped in the they comprise sequences of motor acts which occur in rigid, predictable and highly structured sequence

• 2) FAPs are complex patterns, a characteristic that distinguishes then from simple reflexes.

• 3) FAPS are considered to be shown by all members of a species, or at least by all members of a given sex in appropriate age range and physiological condition within a species.

• 4) FAPS are elicited by simple yet highly specific stimuli.

• 5) FAPS are regarded as self-exhausting; that is the mere occurrence of the FAP reduced the ease with which it could be reelicited. It was not the consequences of the behavior so much as it mere occurrence that made it harder for the behavior to be elicited a second time.

• 6) FAPS are thought to be “triggered”, by which one means that once elicited, FAPs continue independent of external stimulation. Once initiated, a sequence of motor acts would continue even if the environment changed so that the behavior was no longer appropriate. regarded a

Egg Rolling Behavior – Gray lag goose

Vacuous Behavior

• If an egg is out side the nest and the greylag goose will extend its bill to roll the egg back into the nest.

• The egg outside the nest is the releasing stimulus, the extension of the neck and rolling if the FAP.

• If one removes the egg, the goose will continue to act as if the egg was still there.

Innate Releasing Mechanism

• A FAP is viewed as intrinsically organized and held in check by active inhibitory processes in the central nervous system The removal of this active inhibition “released” the behavior and thus permitted it occurrence.

• 7) The occurrence of a FAP is taken to be independent of experience; FAPS are essentially complete on their first occurrence

Sign Stimulus

• The relative simple yet specific stimuli that release fixed action patters

Lure to stimulate aggression in the three-spine stickleback

Male stickleback (bottom fish) trying to entice the female (top fish) into the nest

• The top fish has no red-belly and thus generates no aggressive response by the three-stickleback.

• The remaining three lures have red bellies and thus releases aggressive behavior.

• Note is the stickleback is grazing for food, the red-belly lure terminates the appetitive behavior.

Action Specific Energy

• Faps are thought to be self-exhausting.• For Lorenz, an energy model of behavior was

proposed.• Each FAP was thought to have it own

reservoir of action specific energy.• The amount of energy in the reservoir

increased steadily as the animal refrained from displaying the FAP.

Action Specific Energy (cont).

• The energy level was depleted by the repeated occurrence of the FAP.

• The ease with which the FAP was released was a function of the characteristics of the sign stimulus and the level of action spesific energy at that point in time.

• Much of ethology has been concerned with looking at fixed action patterns of behavior , their releasing stimuli in appetitive, sexing and aggressive behaviors among conspecific animals.

Lorenz Hydraulic Model