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Chapter 12. The Limitations of Learning. Limits. Physical Characteristics Non-heritability Heredity of learning ability Neurological Damage Critical Periods Preparedness Instinctual Drift Biological Preparedness Sign Tracking. Physical Characteristics.
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Chapter 12 The Limitations of Learning
Limits • Physical Characteristics • Non-heritability • Heredity of learning ability • Neurological Damage • Critical Periods • Preparedness • Instinctual Drift • Biological Preparedness • Sign Tracking
Physical Characteristics • Physiological structure of the species • Limitations on behaviours • e.g. teaching chimps to talk vs. teaching sign language
Nonheritability of Learned Behaviour • Learned behaviours are not inherited • Lamarckian evolution: passing acquired characteristics to offspring • Short neck giraffe needs to stretch to reach food • Neck gets longer • Passes on long neck to offspring
McDougall’s rats • Trained rats to run on avoidance task • Trained those rats offspring on avoidance task • Trained those rats offspring on avoidance task, etc. • Each generation should learn faster (inherit skill of parents, and ancestors) • BUT, no control group…
Agar (1954) • Replicated McDougall’s design, but added a control group • Control: every second generation was untrained • Found same pattern of results with control group • i.e. successive generation also learned faster than previous generations • But also many fluctuations within both groups • Suggests that training of parents has no effect on offspring
Non-inheritance • Inheritance of learning could limit adaptability • Advances/changes in ways of thinking • e.g. sun revolves around the earth? • Traditional male/female roles?
Heredity and Learning Ability • Don’t inherit learned behaviours BUT… • Genetic influences on ability to learn • Tryon (1940): rats learn maze, breed “smartest” together and “dumbest” together for 18 generations • ‘Smart’ rats had ‘smart’ rat pups • Not inheriting a learned behaviour, but ability to learn quickly • Identical twins reared apart • Nature and nurture
Neurological Damage • Neurotoxins • Prenatal damage to CNS (e.g., fetal alcohol syndrome, crack cocaine) • Envrionmental toxins (e.g., lead) • Physical damage (e.g., concussions)
Critical Periods • Stage for optimum learning • Puppy dogs • Konrad Lorenz & Imprinting
Harlow & Harlow • Monkeys & terry cloth mothers • “Pit of despair” • Critical period for development of social skills
Preparedness & Learning • Seligman’s ‘Continuum of Preparedness • Prepared • Unprepared • Contraprepare
Autoshaping • Pigeons peck at key light CS even though unnecessary for arrival of US (food) • ‘Prepared’ for learning to peck key-light • autoshaping
Instinctive Drift • Breland & Breland (1961) • “miserly” raccoon • Contraprepared • Innate tendencies (GBTs, FAPs) interfere with learning
Biological Preparedness • Remember ‘bright-noisy water’? • Prepared for ‘flavour’ taste aversion, unprepared for ‘noise’ taste aversion
Learning & Evolution • Like evolution, learning has no specific goal • Not all learning is good • Learned helplessness • Vicarious learning of aggression • Drug conditioning