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Introduction to Psychology
Suzy Scherf
Lecture 6: How Do We Act?
Learning and the
Role of Experience
Psychology without Evolution
Behaviorists -
Nativists -
Psychology without Evolution
Behaviorists and Nativists came up with same
conclusion:
Since learning results from an individual’s experience:
Psychology without Evolution
1. Nature vs. Nurture 2. Genetic Fallacy -
3. Instincts control animal behavior -
Nature vs. Nurture - False Dichotomy
Genetic Fallacy
The idea that traits with a genetic basis are
automatically fixed and inflexible.
Instincts vs. Learning
What do we mean by “instincts”
Instincts vs. Learning
Even animal behaviors that appear to be completely
“instinctual” require learning:
Instincts vs. Learning
What do we mean by “learning”
Instincts vs. Learning
Even animal behaviors that appear to be completely
“learned” are influenced by the genotype:
Psychology with Evolution
1.
2.
3.
4.
Genes Differ in Responsiveness to the
Environment
1. Obligate Effects -
Why Design an Obligate Adaptation?
• When a single solution works best across a wide
range of environments
• Obligate traits ‘expect’ a certain range of environments
Experience Still Matters:
Genes Differ in Responsiveness to the
Environment
2. Facultative Effects -
Why Design a Facultative Adaptation?
1. When the environment is variable within the
lifetimes of individuals.
2. When the fittest alternative varies from one
environment to the next
High
(Phenotype)
Level of Melanin Synthesis
Norm of Reaction for a
Facultative Trait:
Low
Low
(Environment)
High
Level of UVb Radiation
Reaction Range for an
Obligate Trait: Discontinuous
(Range of Normal
Phenotype)
Abnormal
(Range of Normal
Environment)
Abnormal
Selection will prefer facultative or
obligate traits depending on -
What Kind of Learning?
• Learning involves -
• Learning mechanisms are -
• Facultative adaptations are -
What Kind of Learning?
1. Birds learning “star compass” 2. Ants navigation home in most efficient way using
“dead reckoning”
3. Human infants learning language 4. Monkeys showing “insight” in food foraging
What Kind of Learning?
5. Dogs being classically conditioned 6. Cats being operantly conditioned 7. Human’s learning to play a game of weather
forecasting using 8. Monkeys learning to do -
Concepts Relevant to Learning
1. Ecological Context - -
• EEA (Environment of Evolutionary Adaptedness):
Concepts Relevant to Learning
2. Critical Period Learning -
• Specialized to happen once • Indigo Buntings -
• Human’s -
Concepts Relevant to Learning
2. Critical Period Learning • Requires specialized experiences to develop
• Time window • Traits vary in their sensitivity to critical periods
Concepts Relevant to Learning
2. Critical Period Learning • Deprivation and excessive enrichment experiences -
• Related to plasticity
• Different brain systems -
Concepts Relevant to Learning
3. Preparedness -
• Over-prepared -
Concepts Relevant to Learning
3. Preparedness -
• Under-prepared -
Are there any General-Purpose
Learning Mechanisms?
• Can we think of any general problems that animals
face?
• Problems that would be solved with a single learning
mechanism?
Classical Conditioning
• Learning that some external thing can elicit a reaction
from your body
• Forming an association (noticing a pairing) between -
Classical Conditioning is Still not
General-Purpose
Operant Conditioning:
Learning Associations between
Behaviors and Consequences
Operant Conditioning
Reinforcers and Punishers affect behavior
Reinforcers Punishers -
Operant Conditioning
Still not general-purpose
Limitations of Conditioning
1.
2.
3.
4.
Problem-Solving Using Insight or
Trial-and-Error
Problem-Solving Using Insight or
Trial-and-Error