Evolutionary Biology and Social Evolution Flashcards

A set of vocabulary flashcards covering key concepts, mechanisms, and mathematical conditions of evolutionary biology, social evolution, and game theory.

Natural Selection

Differential survival; traits increase because they help organisms survive and pass on genes (e.g., fear of heights, pathogen avoidance).

Sexual Selection

Differential reproduction; traits increase because they help obtain mates (e.g., male-male competition, female choice, peacock tail).

Microevolution

change in gene frequencies across generations

Macroevolution

Large scale evolutionary change and speciation over long periods

Direct Fitness

Passing genes through your own offspring (e.g., having children).

Indirect Fitness

Passing genes indirectly by helping relatives reproduce (e.g., helping your sibling raise children).

Inclusive Fitness

The sum of direct fitness and indirect fitness, representing the total genetic contribution to future generations.

Evolutionarily Stable Strategy (ESS)

A strategy that cannot be invaded by an alternative strategy when common in a population; similar to Nash Equilibrium.

Adaptation

trait that evolved because it solved a survival or reproductive problem

Behavioral Immune System

A psychological system specialized for avoiding pathogens BEFORE infection occurs (e.g., disgust, avoiding sick people, food aversions).

Pathogen Disgust

Disgust that evolved to avoid disease (e.g., rotten food, vomit, feces).

Sexual Disgust

Disgust that evolved to avoid costly mating mistakes (e.g., incest, low-value mates).

Moral Disgust

Disgust directed toward cheaters and norm violators (e.g., theft, betrayal, fraud).

Error Management Theory

Evolution favors less costly mistake

Aggression

Behavior intended to impose costs on another individual

Naturalistic Fallacy

The mistaken belief that because something is natural, it is morally good (natural ≠ good).

Schadenfreude

Pleasure at another's misfortune

Resource Holding Potential (RHP)

Any characteristic increasing the ability to win a contest (e.g., strength, size, weapons, coalition support).

Dominance

Status obtained through fear, intimidation, or coercion, where people comply to avoid costs.

Dominance Hierarchy

Ranked social system based on dominance relationships

Prestige

Status obtained through expertise, knowledge, or skill, where people voluntarily defer.

Badge of Status

Permanent signal of status or fighting ability

Bourgeois Strategy

Play Hawk when owner, Dove when intruder.

threat

Behavioral display signalling aggressive intentions

Kin Selection

Helping relatives because it increases inclusive fitness

Hamilton's Rule

The principle that altruism evolves when relatedness multiplied by benefit exceeds cost ($rB > C$, where $r$ = relatedness, $B$ = benefit, $C$ = cost).

Westermarck Effect

Reduced sexual attraction between individuals raised together during childhood, which supports inbreeding avoidance.

Imprinting

Learning process establishing social or species recognition early in life

Cross-Fostering

swapping offspring at birth to study imprinting effects

Coefficient of Relatedness ®

Probability two individuals share gene from common ancestor

Nepotism

Favoring relatives over non-relatives; evolutionarily explained by kin selection and inclusive fitness.

Direct Reciprocity

A cooperation strategy where 'I help you now, you help me later,' requiring repeated interactions.

Indirect Reciprocity

A cooperation strategy where 'I help you, someone else rewards me later,' driven by reputation.

Tit-for-Tat

A strategy that cooperates first and then copies the opponent's previous move; characterized as nice, retaliatory, and forgiving.

Public Goods Game

A situation where everyone benefits most when all cooperate, but individuals benefit most by free-riding.

Free Rider

Individual benefitting w/o contributing

Tragedy of the Commons

A dilemma where shared resources become depleted because individuals act in self-interest.

Moralistic Punishment

punishing cheaters or norm violators

Network Reciprocity

Cooperators cluster together

Green Beard Effect

Cooperators recognize one another through an identifying marker

Biological Markets

Markets where individuals choose cooperative partners and exchange resources according to supply and demand (e.g., dating, friendships, business partnerships).

Partner Choice

Selection of preferred cooperative partners

Partner Control

Strategies used to prevent cheating by existing partners

Positive Assortative Mating

A pattern where individuals pair with others of similar value (e.g., attractive + attractive, wealthy + wealthy, educated + educated).

Mate Value

An individual's desirability in the mating market, determined by attractiveness, status, resources, and age.

Search Costs

Time, energy, and resources spent finding a partner

Thick Market

Large market w/ many options

Thin Market

Small market w/ fewer options

Signaling

Costly communication providing reliable information that is hard to fake.

Cheap Talk

Low-cost communication that is easy to fake (e.g., dating profile claims).

Fear vs. Phobia

Fear is a response to realistic danger, whereas a phobia is an excessive danger response.

Dominance vs. Prestige

DOminance = fear

Prestige = admiration

Partner Control vs. Partner Choice

Partner control refers to managing an existing partner, whereas partner choice refers to choosing a partner.

Signalling vs Cheap Talk

Signalling = costly and reliable

Cheap Talk = inexpensive and unreliable

Cooperation vs. Altruism

Cooperation benefits both participants, whereas in altruism the actor pays a cost.

Error Management Theory

The evolutionary perspective proposing that false positives are safer than false negatives (e.g., mistaking a stick for a snake).

Bourgeois Strategy

A behavioral strategy where the territory owner acts as a Hawk (fights) and the intruder acts as a Dove (retreats).

Network Externalities

The phenomenon where a service (e.g., a dating website) becomes more valuable as more users join.

Adverse Selection

A market condition driven by hidden information where individuals know more about their own quality than potential partners do.

Condition for Direct Reciprocity

$w > c/b$, where $w$ is the probability of meeting again.

Condition for Indirect Reciprocity

$q > c/b$, where $q$ is the probability reputation is known.

Condition for Network Reciprocity

$b/c > k$, where $k$ is the number of neighbors.

Natural Selection vs. Sexual Selection

Natural Selection = survival.

Sexual Selection = reproduction

Direct vs Indirect Fitness

Direct = own children

Indirect = helping relatives reproduce

Indirect Reciprocity

Reputation

Signaling

Prestige

A billionaire publicly donates money and receives admiration.

Nepotism

Kin Selection

Inclusive Fitness

A father hires his less-qualified son.

Direct Reciprocity

A person helps a coworker because they will work together again tomorrow.

Indirect Reciprocity

Reputation

A student volunteers because admissions officers will see it.

Dominance

People obey a dictator because they fear punishment.

Prestige

People respect a professor because of expertise.

Behavioral Immune System

Pathogen Disgust

Someone avoids spoiled meat.

Sexual Disgust

Inbreeding Avoidance

Westermarck-related mechanisms

Someone finds incest repulsive.

Error Management Theory

False positives are safer than false negatives.

A person mistakes a stick for a snake.

Tragedy of the Commons

A shared fishing area becomes depleted because everyone overuses it.

Free Rider

Public Goods Game

One student contributes nothing but benefits from group work.

Indirect Fitness

Kin Selection

Hamilton's Rule

A person helps their sibling raise children.

Higher RHP

A large strong animal wins a fight over a smaller animal.

Bourgeois Strategy

Owner = Hawk

Intruder = Dove

The owner of a territory fights while intruders retreat.

Positive Assortative Mating

Attractive people pair with attractive people.

Network Externalities

A dating website becomes more valuable as more users join.

Hidden Information

Adverse Selection

People know more about their quality than potential partners do.

Cheap Talk

A person claims online they are more attractive than they really are.

Kenrick et al. (Deep Rationality)

Humans often appear irrational but are actually solving adaptive evolutionary problems.

Tybur et al. (Disgust)

Disgust consists of pathogen, sexual, and moral domains.

Georgiev et al. (Violence Pays)

Aggression evolves when benefits exceed costs.

Henrich & Gil-White

Prestige evolved because humans benefit from learning from skilled individuals.

DeBruine et al.

Facial resemblance functions as a kinship cue.

Nowak

Five mechanisms explain cooperation:

• Kin selection

• Direct reciprocity

• Indirect reciprocity

• Network reciprocity

• Group selection

Camerer & Fehr

Humans are not purely self-interested and care about fairness, cooperation, and punishment.

Barclay

Partner choice drives cooperation because people compete to become desirable partners.

Why does aggression evolve?

When benefits exceed costs.

Why does cooperation evolve?

Mechanisms such as kin selection, reciprocity, network reciprocity, partner choice, and reputation make cooperation beneficial.

Why does nepotism evolve?

Helping relatives increases inclusive fitness.

Why does dominance evolve?

It resolves conflicts while reducing repeated fighting costs.

Why does prestige evolve?

Humans benefit from learning from skilled individuals.

Why does disgust evolve?

To avoid pathogens, poor mating choices, and exploitative social partners.

Why does positive assortative mating occur?

Competition and supply-demand dynamics pair similar-value individuals tog

Four Levels Of Analysis

Causation

Ontoogeny

Function

Evolution

Causation

How does a behavior work

Ontogeny

How does a behavior develop