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Chapter 6
Social Development
Early Child Development
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Gradual progression to full theory of mind
Genetic component driving the stages
Environmental interaction
Social cognition a necessity for more
advanced human social development
Development
• What is the purpose of childhood?
• Humans have extended period before
becoming reproductively capable
– Doesn’t this cut into reproductive success?
• Ultimate explanation: childhood prepares
for adult reproductive phase
Life History Theory
• LHTs see development processes as means
of maximizing inclusive fitness
• Development not a passive process
• “Decisions” during development may be
due to environmental factors interacting
with genes
Principle of Allocation
• Somatic effort
– Foraging, survival, learning, growth, etc.
• Reproductive effort
– Mating, producing, and rearing offspring
• Trade-offs
• No single/unique method for optimization
Reproductive Effort
• Broadly speaking, two techniques
– Quantity: many offspring, limited investment
– Quality: few offspring, high investment
• Environmental constraints determine which
strategy will be most successful
• Male/female differences
Reproductive Strategies: Terms
• Between species
– r: produce as many offspring as possible
– K: produce few offspring
• Between individuals
– C: maximize current fitness
– F: maximize future fitness
– From parent’s or offspring’s perspective
Offspring Predicting the Future
• Attachment strategies due (in part) to
interaction with parents
• Childhood condition serves as model for
future when reproductive phase reached
• How stable/unstable will future be?
• Attempt to maximize reproductive success
– Stable --> future fitness
– Unstable --> current fitness
Correlations with Father Absent
• Precocious sexual development
• Boys more aggressive, rebellious, sexually
exploitative as adults
• Girls have negative sexual attitudes, fewer longterm monogamous relationships as adults
• Single mother family lower economics, lower
resources
• Offspring adopt “current” reproductive strategy to
maximize inclusive fitness
Early Environment
• Maternal attachment theory
– John Bowlby, Mary Ainsworth, Jay Belsky
• Insecure avoidant (~25%)
– Shorter-term relationships
• Secure attachment (~65%)
– Long-lasting, stable relationships
• Insecure resistant (~10%)
– Over commitment to few relationships
Selection
• Insecure avoidant and insecure resistant
seem maladaptive (should have been
selected against)
• But, possibly optimal given different lifehistory environments
• Different attachment styles (acquired during
development) let offspring “plan” for future
Belsky (1997)
• Secure attachment
– Stable developmental environment
– Parenting over reproduction (maximize quality over
quantity; future)
• Insecure-avoidant
– Availability of resources low, parental attention
irregular/inconsistent/unwilling
– Reproduction over parenting (maximize quantity over
quality; current)
• Insecure-resistant
– Speculative; parents unable to contribute?
– Reduce direct fitness, but gain some inclusive
Genes and Environment
• How much of development is genetically
regulated?
• Environment does interact with genome, but
to what extent and when?
• What aspects of the environment are
significant for development?
Behavioural Genetics
• Identifying gene-environment interactions
for specific behaviours
• The old nature-nurture issue
• Monozygotic and dizygotic twins,
biological siblings, adopted siblings
• Same or different environment
• Look for variation in behaviour
Identical Twin Studies
• Genes account for some 40-50% of
variability, environment 50-60%
• Shared environment
– Factors common to all siblings
– 0-10% of environment variability
• Non-shared (unique) environment
– Factors specific to an individual
– 40-50% of environment variability
Non-shared Environment
• E.g., sickness, specific teacher, uterine
environment
• Experiences that one child has but his/her
siblings do not
• Peer groups could be very significant
• Group Socialization Theory
– Judith Harris (1995, 1998)
Group Socialization Theory
• Peers better role model for child than
parents
• Harris argues parents (adults) provide very
little actual guidance/control over
socialization development
Harris: Why Imitate the Young?
• Youth are innovators;
cultural innovation can
increase fitness
• Imitating peers over
parents increases
behavioural variability in
culture
• Parents may not always be
around; peer groups
always are
• Parents and children often
have competing interests
• Individual, not culture that
is level of selection
• Again, culture not the
level of selection
• In EEA orphans have
bigger problems than no
role-model parent; likely
to starve, etc. Any
adopting adult could serve
as teaching model
• Children also compete
with their peers, not just
their parents
Evaluation: Parents have Little
Lasting Socialization Influence
• Many early childhood developmental
studies disagree
• E.g., best predictor of child’s verbal ability
is amount parents talk and/or read to child
• However, there are the behavioural genetics
findings of identical twins reared together
or apart
Evaluation: Importance of Peers
• At this point, Harris’ assertions are
somewhat “just-so stories”
• E.g., Different attitudes in two siblings
could be due to the children joining
different peer groups, but what motivates
joining different groups?
• Could be chance factors (see Pinker 2002)
or interaction between parental behaviour
and child personality (see Vandell 2000)
Belsky (2005)
• Children differentially susceptible to parental
influence; an adaptation in and of itself
– In stable environment beneficial for children to imitate
parents
– In unstable environment, what worked in your parents’
generation may not apply to yours
• World goes through periods of stability and instability
– Might be adaptive for parents to have offspring that will be
differentially susceptible, depending on environmental
conditions
– Belsky proposes ice ages as mechanisms
– But, what about different ethnic groups, or pre- Out of
Africa period?
Social Development: Morality
• The individual is the evolutionary unit of
selection
• Doesn’t moral behaviour act to benefit the
group, though?
• Moral behaviour may have direct benefit to
individuals in the group, though
• Also, remember that in the EEA the group
would have contained more genetic
relatives
Benefit the Group, Benefit Self
• A stable group is a safe, secure group
• The individual in such a group, benefits
from a predictable, stable environment
• This can lead to improved fitness
Example: Reciprocity and
Cheating
• Reciprocal arrangements benefit both parties (i.e.,
everybody wins)
• By cheating, one benefits, one loses
• If cheating becomes common, no benefit to
initiating a reciprocal altruistic interaction
• Now, no one benefits
• Difficult to structure social interactions in an
entirely selfish environment
• If group breaks up, e.g., may be harder to find
food, provide shelter, gain mates, childrear, etc.
Textbook
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Origins of morality
Variability of morality
Universal morality
Well covered in text, so I’m going to leave
it for you to go through this content on your
own
Mirror Neurons
• Scattered throughout premotor cortex,
centres for language, empathy, pain
• Fire when certain actions are preformed by
or observed in someone else
• “Mental imitation” of witnessed (or heard)
actions
Discovery
• Giacomo Rizzolatti, Vitorio Gallese, &
Leonardo Fogassi
• “Raisin incident”
• Macaque monkey with electrodes in
premotor cortex
• Published in 1996
Locations in Humans
• More mirror neurons in more places than in
monkeys
• Premotor cortex (movement)
• Inferior parietal areas (perception)
• Posterior parietal lobe, superior temporal
sulcus, & insula (comprehend another’s
feelings, understand intention, and use
language)
Role
• Learning through imitation
• Understanding meaning or intention of
action
Gallese, et al. (2005)
• Subjects listened to sentences describing
actions
• Same mirror neurons fired as would have if
subjects had done the action or seen the
action performed
• Mirror neurons responded to abstract
representation (i.e., language)
Mirror Neuron Sets
• Iacoboni et al. (2005)
• Basic set: corresponding to an action’s most
essential form (e.g., reaching)
• Supplemental sets: selectively fire
according to action’s perceived purpose
(e.g., picking up glass to drink or to clear
away mess on table)
• Role in understanding intentionality
Empathy
• Wicker (2005)
• Feeling disgust and seeing a look of disgust
activated same set of mirror neurons in
insula
• Allows direct “understanding” of someone
else’s emotional state
• Social cohesion
Mirror Neuron Failure
• Autism
• Mirror neuron trouble may link to problems
with language, learning, and empathy
Studies with Autistics
• Autistic children showed less mirror neuron
activity than normal children when watching
finger movement (basic set failure)
• Both autistic and nonautistic teens imitated and
identify distinctive facial expressions, but the
autistics didn’t show mirror neuron activity
(supplemental set failure); autistics know the
expression cognitively, but felt no empathy