Cultural Diffusion
and
Social Learning Strategies
Advance of a leaned trait
Population: (N0, N+), (Naïve, Informed)
Individual Learning (IL) vs Social Learning (SL)
Advance of a learned trait
Transition (N0, N+)  (N0 – 1, N+ + 1)
IL: Rate Constant, Independent of N+
SL: Rate, per N0, Increases with N+
SL: Signature of Cultural Diffusion
Individual learning: Cumulative
Social learning: Cumulative
Cultural diffusion: Human examples
End of 11th Century:
St Robert Founded First Cistercian Abbey
Slow Growth in Number
1115: St. Bernard, Abbey at Clairvaux
Growth Accelerated
1155: 400 Monasteries
Cistercians in Europe (Grubler 1997)
Cistercians in Europe: Cultural diffusion
Monasteries Communicated
Advanced innovations
Water mill
Wool manufacture
Agriculture/Land clearing (Deforestation)
Cultural Change/Evolution
Opposition to change: Luddites
Fear of new technologies
1811-1816: Luddites destroyed textile machinery
1830: Captain Swing, opposition to threshing machines
Rapidly advancing cultural values
Captain Swing movement: Social learning
Social learning of technology (Grubler 1997)
Cultural diffusion:
Non-human
examples
Reader & Laland
(2000) Anim Behav
60:175
Gupppies: Learn Route
to Rich Food Patch
SL: Following Past
Opaque Partition
Reader & Laland
(2000)
Not signature of social
learning?
Females copied, and
learned faster than did
males.
Males mixed SL and IL.
Social learning, cultural evolution
Common in Humans
Demonstrated in Other Species
Chimpanzees, Macaques
Whale, Bird Song
Cultural Adaptation:
Change in culture increases survival, fecundity
Not as common
Social learning strategies
Laland, K. (2004) Learning & Behavior 32:4.
Commonly assumed: Capacity for social learning adaptive
Gain Information
Avoid Cost of Direct Interaction with Environment
Laland, K. (2004)
Model, Mimic  Producer, Scrounger (Information)
More Social Learners 
Reduced Innovation
Information on Environment Not as Current
More Social Learners 
Fewer Individuals Interact Directly with Environment
Laland, K. (2004)
Use Social Learning Selectively
Mix with Direct Sampling, Trial & Error
Need Strategy for Social Learning
When?
Circumstances for Social Learning?
Whom?
Which Individuals “Best” Information?
Laland, K. (2004): When?
When Established Behavior (No behavior) Unproductive
Pigeons: Food in Cartons, Opened by Tearing Paper
Initially, Most Scrounge Food
Scrounging So Common, Unproductive
Then, Individuals Learn Socially to Open Cartons
Laland, K. (2004)
When Cost of Asocial Learning High
Searching for Resource Patches (vs Following)
Risk of Acquiring Poor Information
Individual Learning Hazardous
Gorillas: Elaborate Processing of Food Plants
Avoid Physical Defenses, Chemical Defenses
Individual Learning Costly
Laland, K. (2004)
When Uncertain
Within-Generation Temporal Variation
Match Behavior to Current Environment
No Obvious Cue to Environment
Rats: 2 Novel Foods – Copy Food Choice by Breath
Familiar Foods – Little Social Influence on Choice
Uncertainty Prompts Social Mimicry
Laland, K. (2004)
Copy Whom?
Directed Social Learning
Identity/Phenotype of Demonstrator
Affects Pr[Social Learning]
Social Rank
Age
Association
Relatedness
Niche
Laland, K. (2004)
Copy the Majority (Conformity)
Mate Choice Copying (Female Choice)
Increase Variance in Rep Success of Other Sex
Copy Rare Behavior
Starlings, Parrots: Copy Song of Other Species
Females Favor Complex Song Repertoire
Laland, K. (2004)
Copy Successful Individuals (vs Successful Behavior)
Easy; Which Traits Imply Success?
Red-Winged Blackbirds: Socially Learn Food Preference,
Demonstrator Becomes Sick/Stays Well
If Strategy Works, Neutral/Maladaptive Trait May
“Hitchhike” with Successful Trait
Laland, K. (2004)
Copy Dominants? Lacks Study
Copy Best vs Copy Better
Cardinal vs Ordinal
Copy Good Social Learners (?)
Copy Kin – Common in Nature
Same Alleles, Same Requirements
Advantage