Download local enhancement -- social facilitation Cultural Transmission

Cultural Transmission – Chapter 6
-- local enhancement
-- social facilitation
Both have the subtopics of:
-- priming (e.g. seeing eating à more
likely to learn about hunting)
-- contagious behavior (mobs)
Mostly relevant for human psychology
Observational learning promoted by…
Observational learning *usually* occurs in social
species. Often considered “social learning”.
Observational / Social learning can lead to cultural
transmission…
-- if it spreads through population
and
-- usually (but not always) if it moves across
generations.
The learned “thing” moving through the population
is a tradition.
How does observational / social learning occur?
Imitation: Observe and reproduce a behavior
that you were unlikely to do yourself.
Copying: Observe and reproduce a behavior
that you normally do. Examples – mate
choice, fear expts mice.
Note: Copying, imitation are anthropocentrically
biased toward vision, but can involve other
senses.
Cultural transmission of potato washing (video 1st
lecture) and stone play (next) in Japanese
macaques
The tradition of stone play observed from its
start over an 8 year period.
As with potato washing, younger individuals more
likely to pick up the tradition and do so sooner.
Younger monkeys
bounce around more
with toys.
Older monkeys spend
more time with toys.
Local enhancement: Others in local
environment do the same thing as
started by one individual.
Local enhancement: fish 2 is doing something that
attracts fish 1 to same area. Fish 1 starts doing the
same thing (foraging). Although not learning from
fish 2, there is social transmission of information.
Social facilitation when starling is attracted to more
starlings, regardless of whether they are doing
something of interest.
Both Local Enhancement and Social Facilitation can
promote social learning, because it provides an
opportunity for individuals to observe each other.
Experiments with Capuchin
monkeys to see if social
facilitation or local
enhancement occurs.
How fast does a monkey try the new food?
Control: Monkey alone,
new food.
Add more monkeys that
don’t have food.
Across barrier – can see
each other.
If social facilitation at
work, original monkey
might be more inclined
to try novel food.
Result: Social facilitation was not a factor.
When gang of monkeys
eating, then focal
monkey more likely to
try novel food.
This implies local
enhancement working.
Example: Social learning in pigeons
Pigeon watches another use its foot in an
operant conditioning paradigm. Observer then
learns it in fewer trials, or instantly.
Example 2: More birds.
Step 1: Early 1900's, England: Robins & titmice
individually learn to slurp cream off the top of milk left
on doorsteps.
By 1920's, milk
distributors put foil
caps on the left
bottles.
Step 2: individual robins & individual titmice learn to
poke through the foil caps to get at the milk.
Step 3: Cultural transmission of learned behavior
occurs, but only in titmice, all of whom quickly learn
how to get milk.
Why is there not cultural transmission in robins?
Territorial
Fledglings are
compelled to disperse
vs.
Titmice (Parus
palustris)
Robins (Erithacus
rubecula)
Flocking, social group
Fledglings stay in natal group
for several months
Imitation learning in mammals
(bats, chimpanzees, humans)
Panamanian bat finds Physalaemus frogs to eat
by listening for the frog’s advertisement call.
Frog-eating bat,
Trachops cirrhosus
(plus ½ a Physalaemus
pustulosus)
Cane toad, Bufo
marinus (Much too
large for bat to eat)
Reference: Page & Ryan, Current Biology 16:1201-1205
Experiment set #1:
Place loudspeaker next to captured palatable
prey (Physalaemus pustulosus) but play call of
another sympatric frog species (Bufo marinus)
that is (i) toxic and (ii) way too big for the bat
to handle.
Result: Bats learn association and will be
attracted to wrong species.
Experiment set #2:
a) Train one bat to make the acoustic association
of B. marinus advertisement call with a good food
reward (= tutor).
b) Allow an inexperienced bat to observe (only)
the tutor fly to the loudspeaker and get a reward.
(Association made only if loudspeaker playing
correct sound.)
Result: The second bat learned from the first bat
(mean of 5.3 +/- 1.7 trials). Some control bats
learned the association, but this took 83 trials!
Experiment set #2 cont’d:
c) Use 2nd bat as tutor for a third bat, etc. The
new skill was socially/culturally transmitted
without fade in 10 bats.
Tool use - imitation learning in chimpanzees
Ans: chimp does not already know how to do it; it is novel
Why is this not “copying”
Kids imitate adults. Best parenting advice ever: You should
not be worried that your kids don’t listen to you, but
concerned that your kids are always watching you.
From Wikipedia, follow up study:
“48 girls and 48 boys were divided into 3 experimental groups and 1
control group. Group 1, watched a live model become aggressive towards
the Bobo doll. Group 2, watched a film version of the human model
become aggressive to the Bobo doll and group 3 watched a cartoon
version of a cat become aggressive towards the Bobo doll. Each child
watched the aggressive acts individually. Following the exposure to the
models all fours groups of children were then individually placed in a room
with an experimenter where they were exposed to a mildly frustrating
situation to elicit aggression. Next the children were allowed to play freely
in an adjoining room, which was full of toys, including the Bobo doll and
the "weapons" that were used by the models. The researchers observed
the children and noted any interaction with the Bobo doll.
Results showed that the children who had been exposed to the aggressive
behavior, whether real-life, on film or cartoon, exhibited nearly twice as
much aggressive behavior than the control group. It was also found that
boys exhibited more overall aggression than girls. The results of this
experiment shed light on how influential media can be on children and
their behavior.”
The neural basis for imitation: mirror neurons
Raster plot and histogram of response from one neuron. Each
dot is one action potential.
Monkey’s neuron responds
more strongly when it grabs
Monkey’s neuron
food with its own hand.
responds when
human hand puts
food on tray.
Monkey’s neuron does not
fire when food is placed with
a pair of pliers!
Monkey’s neuron fires when
it retrieves food but cannot
see what it is doing à not a
visual neuron.
Copying
Female guppies copy preference of another female
male
observer
female
model
female
male
Step 2: Glass barriers removed and model female gets
to swim toward preferred male. Observer female sees
which male is preferred by model female.
male
observer
female
model
female
male
Step 3: Model female removed and observer female
let out of cylinder. Observer female chooses same
male as model female (17/20 times).
male
observer
female
model
female
male
Step 3: Model female removed and observer female
let out of cylinder. Observer female chooses same
male as model female (17/20 times).
Is this significant?
What test would you use?
H0?
Sign and binomial test
Number of "successes": 17
Number of trials (or subjects) per experiment: 20
Sign test. If the probability of "success" in each trial or
subject is 0.500, then: The one-tail P value is 0.0013
This is the chance of observing 17 or more successes in 20
trials.
The two-tail P value is 0.0026
This is the chance of observing either 17 or more
successes, or 3 or fewer successes, in 20 trials.
Guppies also have an innate preference for
orange body color.
Step 1: Female 1 gets choice of 2 non-orange
males.
Female 2 watches female 1 & learns preference
Step 2: Female 2 gets choice of female 1’s
preferred male and an orange male!
Female 2 choice:
It depends on how
orange!
Light orange:
Copying over-rides
innate preference.
Very orange: Innate
over-rides cultural
transmission.
Copying behavior in mammals.
Step 1: Mouse 1 observes mouse 2 getting a bite from
stable fly and then hiding in response.
Step 2: Stable fly put in cage with mouse 1
Before being bitten, mouse 1 buries itself
Copying behavior in mammals.
Step 1: Mouse 1 observes mouse 2 getting a bite
from a stable fly, and then hiding in response.
Step 2: Stable fly put in cage with mouse 1
Before being bitten, mouse 1 buries itself.
One meerkat trained to prefer a particular
random shape. Others in group developed same
preference… for a while.
Preferences obtained by
copying a model
individual may last a
short while, especially if
preference is arbitrary.
Encouraging copying: Teaching.
Meerkats do this – helpers bring incapacitated
prey (scorpions) to pups & help them learn how to
remove stingers, etc.
Cultural Information transfer may be…
Vertical
Parent à Offspring
Horizontal
Peer à Peer
Vertical transfer
– young birds learn song from parents
Oblique transfer
– any adult rhesus monkey showing fear of
snakes will cause young monkeys to fear snakes.
Horizontal transfer
– fish learn a preferred path from peers in
their school.