Social Hierarchies

What is it?

• Structured system of ranking people in a group
  • Ranking might be based on dominance or status
• Leads to unequal access to resources & opportunities

Examples

Lobsters:

• Male lobster fight when they first meet
• The winner gets dominance and thus better access to food + mates

Children & social ranking:

• Children rank each other from a young age
• Kids know who is the ‘toughest’ in the group

Humans as status strivers:

• Hierarchy is reinforced in language (winner vs loser)
• Humans innately seek status
• Historically hierarchy allowed for better large scale coordination
  • Pyramids of Giza
  • Clear leadership

Egalitarian vs Hierarchical Societies

	Egalitarian	Hierarchical
Features	Emphasis on sharing & humility. Minimise personal success and use humour to manage egos. No one has formal authority.	Develops when groups are able to accumulate resources. Costly signalling = people who control resources display their wealth lavishly Conspicuous consumption= buying luxury things that have little use
Examples	San of the Kalahari	Peacock’s tails

Advantages & Risks of Hierarchical Societies

Pros:

• Reduces conflict
• Efficient decsion-making
• Coordination of complex tasks
• Encourage cooperation & sacrifice

Cons:

• Inequality
• Less opportunities for people of a lower rank
• Abuse of power

Power & Status

Power = the freedom to act or influence decisions

Status = the level of respect & prominence given to someone based on group evaluation of their attributes

Types of Power

Reward Power	The ability to give rewards for compliance
Coercive Power	The ability to threaten punishment for non-compliance
Informational Power	The target’s belief that the influencer has more information than themselves
Expert Power	Target’s belief that the influencer has greater expertise and knowledge than themselves
Legitimate Power	Target’s belief that the influencer is authorised by a recognised power structure to make decisions
Referent Power	Identification with, attraction to or respect for the source of influence

Manipulative Leadership

Limits of Manipulative Leadership

• Negative social consequences constrain them
  • Gossip
  • Reputation harm
  • Group norms
• Punishment from the community
  • 17th Century German ‘Shame Masks’
• People don’t respect them

Power from Below

• Leadership based on cooperation = highly effective

Chenoweth & Stephan (2008)

• Analysed 323 opposition movements between 1900 – 2006
• Nonviolent movements 2x as successful as violent movements (53% goals achieved vs 26%)
  • Nonviolent = protests, petitions, boycotts
  • Violent = bombings, assassinations, coercive tactics

Elements of an Effective Leader

Expertise:

• People with relevant knowledge improve group performance
• Allows them to make informed decisions
• Helps them guide people

Social Skills:

• Social & outgoing people build create positive group dynamics

Generosity:

• People who share group resources in everyone’s best interest gain rspect
• Signals commitment
• Fosters trust & loyalty

Power, SES & Altruism

Approach/ Inhibition Theory

• A theory that states that power acts as a psychological accelerator or brake
• Shows how power affects behaviour

High Power –> Approach Orientation

People with high power:

• Focus on goals & rewards
• Make quicker decisions
• Act with less contraints
• Less sensitive to other people’s feelings
• Rely more on stereotypes
• Get a ‘green light’ to act

Low Power –> Inhibition Orientation

People with low power:

• Act more cautiously
• Attend to other peope
• Monitor & inhibit their behaviour
• More sensitive to social cues
• Reduced cognitive flexibility
• Have a ‘yellow light’ and move more carefully

“E on the Forehead Study” (Galinsky et al., 2006)

• People told to think about a time they had high power or low power
• They were asked to draw a letter E on their head for another peson to read it
• High power group = drew it from their perspective
• Low power group = drew it for the perspective of others

Power & Empathy

• Power can reduce empathy but doesn’t always lead to antisocial behaviour
• If high power person is prosocial –>power amplifies this
• Power is an accelerator for people’s natural traits

Power & Socioeconomic Status

Key components of SES

Wealth/ Income	The amount of money and assets a person or family has, such as salary, savings, or property ownership.
Education	The highest level of schooling completed, such as high school, college, or advanced degrees.
Occupational Prestige	The social standing or respect associated with one’s job or profession, like being a doctor, teacher, or artist.

SES & Everyday Behaviour

Speech & Language patterns:

• Accent, vocabulary, formality
• How you speak shows your class

Clothing & consumption patterns:

• The brands you like can signal your class
• Influences how people perceive you

Social Networks & Affiliations:

• Who you are connected to is linked to SES
• Shapes your access to resources

SES on Generosity & Altruism

• Mixed results
• Some studies found lower income people donate a larger proportion of their income

SES & Prosociality

Lower SES = More Giving

Piff et al. (2010)

• In the dictator game, lower class players gave more points to strangers
• Lower SES people more likely to take on harder tasks to reduce burden on other people
  • Difference disappeared after everyone watched a compassion-inducing film clip
  • Power brings to the front underlying motivations

Higher SES = More Rule Violation

• People with higher SES more likely to break rules
• Drivers of expensive cars more likely to break traffic rules

Lower SES = Less antisocial

• Large surveys showed that high SES people are more likely to admit to minor crimes
• Might reflect differences in woh is prepared to own up to unethical behaviour
• Wealthy people might be less suspicious

Methodological Challenges

• Some studies failed to replicate original findings
• Some show no relationship between SES & prosocial behaviour
• inconsistent findings

SES & Returning a Misdelivered Letter

(Andreoni et al., 2021)

• Field study in the Netherlands to see is SES impacted who would return a misdelivered letter

Method:

• Households received a letter to the wrong address with money inside

Findings:

• Higher SES households more likely to return the letter, especially when it contained cash over a bank transfer card
• Altruistic behaviour varies across socioeconomic contexts

Cooperation & Evolution

Cooperation in Human History

• Important for survival & social development
• Cooperative childcare
• Group hunting
• Forming alliances

Proximal causes of cooperation

• Immediate motivations behind cooperative behaviours
• Feelings & incentives driving people to help each other

Distal Causes of Cooperation

• Long-term evolutionary benefits driving cooperation
• Benefits for survival + reproduction
• Sharing resources –> builds alliances

Key Concepts

Inclusive Fitness	Inclusive fitness is the total genetic success an individual achieves through their own reproduction (direct fitness) and by helping genetic relatives reproduce (indirect fitness)
Direct Fitness	Genetic success gained by producing and raising one’s own offspring.
Indirect Fitness	Genetic success gained by helping relatives (other than one’s own children) survive and reproduce.
Kin Selection	Kin selection is the evolutionary process in which individuals help genetic relatives, increasing the survival of shared genes and thereby enhancing inclusive fitness (e.g., meerkat sentinels)

Inclusive Fitness Theory (Hamilton, 1964)

• Explains how helping behaviour persists even at personal cost
• Our individual genetic success depends on the reproduction of genetic relatives
• Helping relative survive to reproduce increases shared genes passing down

Examples of Kin-Directed Altruism

• Meerkats take turn standing guard while the group forages
• Haldane’s 2 brothers or 8 cousins
• People are more likely to help more close relatives in life or death situations

Cooperating with Non-Relatives

Driven by reciprocal altruism

Vampire bats sharing blood (Carter & Wilkinson, 2013)

• Bats will share blood via regurgitation to the bats that have no food
• They are more likely to help those that have helped them before
• Reciprocal exchange

Chimpanzee grooming & food sharing (Jaeggi et al., 2013)

• Chimps groom each other to build trust and social bonds
• More likely if it is reciprocated

Human reciprocity (Strohmetz et al, 2002)

• Humans tend to return acts of kindness
• More likely when they feel appreciated
• Gratitude reinforces the behaviour

Game Theory & Cooperation

The Prisoner’s Dilemma

Definition

A classic game theory model examining the tension between:

• Cooperation
• Self-interest (defection)

Two individuals independently choose whether to:

• Cooperate
• Defect

Their outcomes depend on both players’ choices.

Key Insight

Acting in pure self-interest can lead to worse outcomes for everyone.

One-Shot Prisoner’s Dilemma

One-Shot Game

• Played only once.
• No future interactions.

Best Individual Strategy = Defect

Reason:

• Defection gives the highest payoff regardless of what the other person does.
• Therefore defection is the rational choice in a single interaction.

Repeated Prisoner’s Dilemma

Repeated Interactions

Most real-life relationships involve repeated encounters.

Examples:

• Friends
• Families
• Coworkers
• Nations

Why Repeated Games Matter

People can:

• Remember previous behaviour.
• Reward cooperation.
• Punish defection.

This creates conditions where cooperation can become advantageous.

Strategies in Repeated Games

Always Cooperate

Characteristics

• Cooperates every round.
• Never retaliates.

Advantages

• Builds trust.
• Maximises mutual rewards if both cooperate.

Disadvantages

• Easily exploited by defectors.
• Performs poorly in mixed groups.

Always Defect

Characteristics

• Defects every round.

Advantages

• Gains short-term benefits.

Disadvantages

• Prevents long-term cooperation.
• Often performs poorly overall in repeated interactions.

Axelrod’s Tournament

Researcher

Robert Axelrod

Study

Researchers submitted computer strategies to compete in a repeated Prisoner’s Dilemma tournament.

• Every strategy played:
  • 200 rounds
  • Against every other strategy

Goal:

• Find the most successful strategy in repeated interactions.

Winning Strategy: Tit-for-Tat

Rules

1. Cooperate on the first move.
2. Never defect first.
3. If the other defects → retaliate next round.
4. If they return to cooperation → cooperate again.

Characteristics of Tit-for-Tat

1. Nice

• Starts cooperatively.
• Doesn’t initiate conflict.

2. Retaliatory

• Responds to defection.

3. Forgiving

• Returns to cooperation if the other player does.

4. Clear

• Predictable and easy to understand.

Why Tit-for-Tat Works

It:

• Promotes cooperation.
• Prevents exploitation.
• Encourages reciprocity.
• Creates mutually beneficial relationships.

Exam Point

In a repeated Prisoner’s Dilemma:

Tit-for-Tat is most likely to foster ongoing cooperation.

Axelrod’s Conclusion

Cooperation can evolve when:

• Interactions are repeated.
• Individuals remember past behaviour.
• Defection can be punished.
• Cooperation can be rewarded.

Important

Tit-for-Tat was not best against every individual strategy.

However:

It achieved the highest overall success across many different strategies.

Real-World Applications

1. International Arms Control

Cooperation

Countries limit weapons.

Result:

• Greater collective safety.

Defection

One country builds more weapons.

Result:

• Competitive advantage.

Outcome

If both defect:

Arms race

Solution

• Repeated negotiations
• Trust-building

2. Group Projects & Social Loafing

Cooperation

Everyone contributes.

Result:

• Better group performance.

Defection

Some members free-ride.

Result:

• Unfairness
• Frustration
• Reduced performance

Tit-for-Tat Approach

• Start cooperatively.
• Adjust behaviour according to others’ effort.

3. Environmental Cooperation

Examples:

• Climate agreements
• Pollution reduction
• Resource conservation

Cooperation

Everyone contributes.

Result:

• Environmental benefit.

Defection

Some gain short-term advantages.

Result:

• Long-term environmental harm.

Solution

• Monitoring systems
• International agreements

Reputation

Definition

Reputation = social information about an individual’s past behaviour.

Why It Matters

People with good reputations are more likely to:

• Be trusted.
• Be included.
• Receive help.

People with bad reputations are more likely to:

• Be avoided.
• Be excluded.
• Lose opportunities for cooperation.

Key Idea

Reputation acts as a form of social currency.

Gossip and Ostracism

Gossip

Definition

Sharing information about others’ behaviour.

Functions

• Identifies cooperators.
• Identifies cheaters.
• Spreads reputational information.
• Helps enforce group norms.

Gossip is not always negative.

It often promotes:

• Trust
• Cooperation
• Social learning

Ostracism

Definition

Excluding or avoiding people who violate group norms.

Function

Acts as punishment for:

• Cheating
• Free-riding
• Norm violations

Combined Effect

Gossip + Ostracism

Together they:

• Increase cooperation.
• Discourage cheating.
• Promote fairness.
• Strengthen group norms.

Cheater-Detection Adaptations

Definition

Evolved cognitive mechanisms that help humans identify cheaters.

Cheater

Someone who:

• Receives benefits
• Avoids paying associated costs

Key Terms

Cheater-detection adaptation	An evolved mental ability that helps us recognise individuals who violate social rules or take unfair advantage in exchanges.
Wason selection task	A logic puzzle used to test reasoning; people struggle with abstract versions but excel when it involves detecting social rule violations.
Social exchange version	When the Wason task is framed as a social contract (e.g., underage drinking), most people easily identify rule breakers.

Why Cheater Detection Matters

Supports reciprocal altruism by helping people:

• Recognise defectors.
• Avoid exploitation.
• Punish cheating.
• Maintain cooperative relationships.

Wason Selection Task & Social Exchange Theory

Wason Selection Task

A logic task developed by Peter Wason to test reasoning using conditional rules:

If P, then Q

Key Finding

People perform poorly when the rule is abstract.

Example:

If a card has a vowel on one side, it has an even number on the other.

Most people choose the wrong cards.

Social Contract Version

When the same logic is framed as a social rule, performance improves dramatically.

Example:

If a person drinks beer, they must be over 18.

People easily identify which cards to check because they are looking for:

–> Cheaters (someone getting a benefit without meeting the requirement).

Social Exchange Theory

Developed by Leda Cosmides.

Main Idea

Humans evolved specialised cognitive mechanisms for social exchanges involving:

• Costs
• Benefits
• Cooperation
• Cheating

We are especially good at reasoning when we need to identify people breaking social rules.

Cheater Detection Adaptation

An evolved mechanism that helps us detect individuals who:

• Receive benefits
• Without paying the associated costs

Example:

• Drinking alcohol while underage
• Entering without a ticket
• Taking rewards without contributing

Why It Matters

Cheater detection helps maintain:

• Reciprocal altruism
• Cooperation
• Fairness within groups

Without it, cooperation would break down because free-riders could exploit others.