Introduction to PsychologySuzy 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
Norm of Reaction for a Facultative Trait:
Level of UVb Radiation
Low HighLow
High
(Environment)
(Phe
noty
pe)
Lev
el o
f M
elan
in S
ynth
esis
Reaction Range for an Obligate Trait: Discontinuous
(Range of Normal Environment)
(Ran
ge o
f N
orm
al
Phe
noty
pe)
Abnormal
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 notGeneral-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
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2.
3.
4.
Problem-Solving Using Insight or Trial-and-Error
Problem-Solving Using Insight or Trial-and-Error