Chapter 7: Play and aggression
Thesis of chapter: That NS favored restrained
aggression in humans and rough-and-tumble
play was critical to this selection process.
Restrained aggression and rt play
• Observational evidence:
• Lethal aggression among conspecifics is rare in animal world,
displays and ritual aggression are more the norm
• Lethal aggression varies, but is not common among nomadic
foragers and is usually for personal, not collective reasons
• Evidence from animals and human children indicates that rt play
serves as a venue for development of social skills, assessment of
an opponent’s strength, sensitivity to dominance/submission cues
and restraint in aggression.
(Non-predatory) Aggression among animals
• rarely “fight to the death” Why
not: all out aggression is costly,
even the eventually winner may
suffer debilitating fitnessthreatening injuries. Better for
the winner to save energy and
loser to live to fight another day.
• Display: Non-contact signals of
intent and quality. Ex: roaring
contests among lions or deer.
Displays out number aggression
60:1 among elephant seals.
• Ritual contest: stylized fighting
with implicit rules. Ex: heat
butting among big-horn sheep;
antler wrestling among caribou.
Chimpanzees
• Note: not mentioned
by author but among
closest human relatives
– chimpanzees both
display and fight, fights
can sometimes be
quite violent and
occasionally lethal.
They display more and
ritualized gestures of
dominance and
submission serve to
regulate fights.
Aggression in the EEA
• Reconstruct the EEA by looking for
recurring patterns in nomadic huntergatherers
• Violence in nhgs: (1) avenging death of
family member, (2) males fighting over
females, (3) collective violence against a
“bad” group member.
• Non-violent dispute resolution: (1)
leaving group either collectively or
singly; (2) avoidance; (3) gossip or
ostracism; (4) group meetings, (5)
ritualized contests
Dealing with out-groups
•
•
•
•
Avoidance
trade
gift-giving.
Since nhg own very little are highly mobile they almost
never fight over land, resources, possession – most
common things people fight over today. Thus, little if any
organized, militaristic fighting or warfare.
Display and contest among nomadic hg’s
• Verbal abuse: sitting around
campfire; drum matches;
• Contests: wrestling matches,
exchange of blows; ordeal rituals
• In most cases winning a contest
fairly enhances status, cheating
leads to ridicule, shame.
• Factors militating against too much
aggression among h-gs: (1) strong
need for cooperation; (2) presence
of kin within groups (inclusive
fitness); (3) severe risks of being
outcast; (4) revenge ethic
Role of R-T play in restrained aggression
• Common among larger-brained social animals,
especially mammals and primates
• Universal among healthy, typically-developing
children including h-g children
• Undoubtedly would have been present among
children in our ancestral past
Role of R-T play in restrained aggression
• Two assertions
regarding r-t play and
aggression
• In children: it plays an
important role in
learning restraint in
aggression
• In adolescents:
important for learning
rule-based contest
nature of aggression
Evidence
• Lack of rt play has been associated
with poor social skills and inability
to distinguish play from real
aggression
• Rats raised without rt play overreacted to benign social contact,
treated it as an attack
• Male mice raised only by females or
monkeys raised without conspecific
interaction both showed heightened
aggressive reactivity
• Human children increased rt play
associated with social competency
Evidence
• Shift in rt function with age – younger children: practice function
for physical skills; older children: dominance function in
determining strength and social status.
• In older boys: rt can vary in seriousness as play sessions progress,
serious until submissive act, then play resumes, suggesting a
restrained way of determining social status.
• Intermingling of serious aggression and play fighting in older boys
(mostly) parallels h-g contests where serious matters are handled
with rules and restraint, not all out aggression