Multilevel Societies

Question 1

What are multilevel societies (MLS)

Answer 1

Most complex social systems that have multiple distinct social levels, where social levels are nested within each other - each level includes the one above it

Question 2

Describe humans in multilevel societies

Answer 2

Humans belong to different social groups and transition in/out depending on different circumstances

Question 3

Which primates have multilevel societies (5)?

Answer 3

1) Asian colobines such as a) snub-nosed monkey, b) douc langurs, c) proboscis monkey
2) Cercopithecines such as a) geladas and b) hamadryas baboons

Question 4

How is the structure of MLS defined?

Answer 4

1) At least 2 stable and consistent levels that separate the individual from the population (core unit, upper level)
2) The number of social levels and names given to levels differs among species
3) Social levels get larger and less socially cohesive moving down levels

Question 5

What is the core unit in non-human primates usually?

Answer 5

OMU

Question 6

What is the upper level in non-human primates usually?

Answer 6

Bands

Question 7

What does the gelada MLS look like?

Answer 7

1) Core = unit (OMU or AMU)
2) Intermediate = team
3) Upper = band/ecological unit (sleep and forage together)
4) Apex = community (associations occur over the span of years)

Question 8

What does the hamadryas baboon MLS look like?

Answer 8

1) Core = OMU
2) Intermediate = clan (OMUs + some solitary males)
3) Upper = band
4) Apex = troop

Question 9

What does snub-nosed monkey MLS look like?

Answer 9

1) Core = OMU
2) No intermediate
3) Upper = band
4) Apex = troop

Question 10

What does hunter-gatherer human MLS look like?

Answer 10

1) Core = family
2) Intermediate = extended family
3) Upper = band
4) Apex = community tribe

Question 11

What are core units?

Answer 11

1) Highly cohesive/stable
2) Stay in regular/permanent proximity (spatially and socially)
3) Usually OMUs

Question 12

What makes the OMUs of hamadryas baboons so special?

Answer 12

Hamadryas baboons have OMUs but also have follower males in the group (do not sire offspring)

Question 13

What are intermediate levels?

Answer 13

1) Closely associated core units
2) Clans/teams
3) Interact with units in the same clan than units outside of clan

Question 14

What are upper levels?

Answer 14

1) Consist of core units (and intermediate levels)
2) Must be stable enough to be recognized (i.e., recurring groupings that can be observed regularly)
3) Membership can be consistent or probabilistic (come together or separate based on circumstances)

Question 15

What are apex levels?

Answer 15

1) Temporary aggregation of upper levels (typically at sleeping or foraging sites)
2) Distinctively large

Question 16

How do we quantify social levels?

Answer 16

By calculating the association time (Snyder-Mackler)
1) Core units spend 100% of time together
2) Teams >90%
3) Bands >50%
4) Community <50%

Question 17

What is fission-fusion?

Answer 17

Cleaving and coalescing to form subunits in response to socioecological factors (food, predation, mating)

Question 18

What does fission-fusion look like in MSL?

Answer 18

Cleaving and coalescing into different social levels, but individual within levels remain the same

Question 19

What are the adaptive functions of MLS?

Answer 19

Helps balance costs and benefits of group living, where different functions can be optimized at different social levels

Question 20

What are some examples of adaptive functions in MLS of hamadryas baboons?

Answer 20

1) OMU = reproductive partners
2) Clan = maintenance of male-male relationships
3) Band = predator protection and resource defense
4) Troop = predator protection at sleeping cliffs

Question 21

What are some general examples of adaptive functions of MLS?

Answer 21

1) Clans can split into individual units when food availability is low
2) Units can come together as a clan in the presence of predator/bachelor threats

Question 22

How did multilevel societies come to be for geladas and hamadryas baboons?

Answer 22

1) Originally large multi-male/multi-female groups
2) Large groups sizes were due to localized resources
3) High aggression and harassment by unfamiliar individuals resulted in splitting into OMUs (for male reproduction and female protection)

Question 23

How did multilevel societies come to be for snub-nosed monkeys?

Answer 23

Independent OMUs emerged due to persistent threat of infanticide from bachelor males

Question 24

What is the social structure of gelada core units?

Answer 24

1) Shaped by kin bonds among females (female-female bond)
2) OMU or AMU

Question 25

What is the social structure of hamadryas baboons core units?

Answer 25

1) Pair bonds between leader male and his females (male-female bonds)
2) OMUs

Question 26

What is the unifying force that links social levels together?

Answer 26

Kinship

Question 27

Describe kinship among hamadryas baboon females

Answer 27

1) Female dispersal is limited to bands
2) Females are more closely related maternally within OMUs
3) Leader and follower males are closely related maternally
4) Kin selection among females likely an organizing principle of MLS

Question 28

What are some consequences of MLS?

Answer 28

1) Reproductive units and bachelor males live closely
2) High intrasexual selection (high density of competitors) = evolution of signals of male quality
3) Males have more developed sexually dimorphic traits
4) Asian colobines exhibit greater sexual dimorphism in body size

Question 29

What does sexual dimorphism look like in MLS vs multi-male/uni-female and monogamous societies?

Answer 29

Sexual dimorphism is more pronounced in MLS compared to other societies

Question 30

What is an example of monogamous monkeys that exhibit low sexual dimorphism?

Answer 30

Titi monkeys