Blood Revenge, Kinship, and Conflict: Anthropology and Game Theory

What is blood revenge?

Killing in retaliation for the death of one's kin.

What can the target of blood revenge be?

The perpetrator of the original homicide or one of the perpetrator's kin or community.

What phenomenon can blood revenge fuel?

Blood feuds, which are retaliatory killings between kin groups that can persist over generations.

What did Daly and Wilson find regarding blood revenge across societies?

Blood revenge was nearly ubiquitous, with 57 of 60 societies mentioning blood feuding or capital punishment.

What was the conclusion of Otterbein and Otterbein about blood feuds?

In their sample, blood feuds were mostly infrequent or absent, as they measured alternatives to feuds rather than their frequency.

Which type of society is most likely to engage in blood revenge?

Pastoral societies, due to the high risk of theft of resources and women.

What is a major source of conflict underlying blood revenge?

The theft of women and resources.

Why are pastoralist societies at high risk of theft?

Livestock are extremely valuable and can be easily raided.

What must victims of theft and violence do in the absence of authority?

Resort to self-help justice to deter future attacks and eliminate rivals.

What social structures can lead to fraternal interest groups?

Patrilocal residence and polygynous marriage.

What are co-unokais among the Yanomamö?

Men who kill together, live in the same village, and exchange women with each other.

What is the relationship pattern preferred by Yanomamö men for marriage exchange?

Cross-cousin marriage, ideally with maternal cousins.

What advantage do larger coalitions have in conflicts?

They can better defend themselves and avenge attacks.

What is the common argument for limiting blood revenge?

That extreme retaliation harms society.

What does inclusive fitness interest mean in the context of revenge?

Caring for groups only to the extent that they further individual interests.

What is the Prisoner's Dilemma (PD) in game theory?

A scenario where individuals can either cooperate or defect, with specific payoffs for each choice.

What is the expected payoff for always defecting in the Prisoner's Dilemma?

Always greater than cooperating when partners only interact once.

What strategy can evolve through repeated interactions in the Prisoner's Dilemma?

Reciprocity, where individuals respond to their partner's actions.

What is the ***-for-Tat strategy in the Prisoner's Dilemma?

Cooperate on the first round and mirror the partner's behavior in subsequent rounds.

What can happen if a ***-for-Tat partner accidentally defects?

It can lead to long cycles of defection and feuding.

What is the Pavlov strategy in the Prisoner's Dilemma?

A strategy that follows 'Win-Stay, Lose-Shift' to avoid feuding cycles.

What influences the choice between 'an eye for an eye' and all-out war?

The expected outcomes of actions for oneself and one's kin.

What is the Hawk-Dove game in relation to aggression?

A game that illustrates the evolutionarily stable strategy for aggression based on resource value and fighting costs.

What should individuals do when fights are costly relative to the resource value?

Limit their aggression.

What happens when the costs of aggression decrease?

It may pay to escalate to war.

What is vassalage in the context of agricultural societies?

A system where society is organized around service to landowners rather than kinship.

How does a central authority affect the administration of justice?

It tends to take over the administration of justice to maintain peace and revenues.

What is the benefit of impartial, third-party justice?

It removes the incentive for protracted blood feuds and protects individuals from outside threats.

What is a potential downside of justice without revenge?

Families of victims may feel unsatisfied with the outcome, as there is no place for them in the prosecution.

According to Quinsey et al. (1999), how does genetic relatedness affect perceptions of crime severity?

Perceptions of severity and upset feelings increase with genetic relatedness.

What are the two alternative hypotheses regarding raiding parties in a pastoralist society?

1. Composed of fraternal interest groups (Daly and Wilson). 2. Composed of marriage exchange partners (Macfarlan et al.).

What does the dataset 'class-dataset06-pairs-relatedness.csv' contain?

Synthetic data on 500 pairs of men who have killed together, including genetic relatedness and number of co-kills.

What relationship do Daly and Wilson expect between genetic relatedness and co-kills?

A positive relationship between relatedness and the number of co-kills.

What relationship do Macfarlan et al. expect between genetic relatedness and co-kills?

A positive relationship between relatedness and the number of co-kills.

What is one method to visualize the relationship between two quantitative variables?

Producing a scatterplot.

What should be done to clean up a scatterplot?

Remove gridlines, add axis titles, set maximum x-axis value, and add a linear trend line.

What kind of relationship might be observed in a scatterplot of genetic relatedness and co-kills?

A positive and roughly linear relationship.

What is the significance of blood revenge in the context of kinship?

It reflects the organization of social structures around familial ties and the desire for retribution.

What societal structure may arise from agricultural dependence?

A structure organized around service to landowners rather than kinship.

What is the role of a central authority in maintaining peace?

To serve the interests of the authority and protect individuals from outside threats.

How might families of victims react to third-party justice?

They may feel upset that there is no place for them in the prosecution process.

What does the term 'genetic relatedness' refer to in this context?

The degree of genetic connection between individuals, influencing perceptions of crime severity.

What hypothesis suggests that moderately related individuals are most likely to kill together?

An inverted U-shaped relationship proposed by Macfarlan et al.

What is the expected outcome of a scatterplot analysis in this context?

To determine the nature of the relationship between genetic relatedness and co-kills.

What might be a reason for families feeling justice is not served?

The absence of personal involvement in the prosecution process.

What does the term 'blood feuds' refer to?

Long-standing conflicts between families or groups, often involving cycles of retaliation.

Why might a society prefer third-party justice over personal vengeance?

To avoid ongoing cycles of violence and maintain social order.

What are the implications of justice systems on societal behavior?

They can reduce the prevalence of personal revenge and promote stability.

What does a positive correlation (r > 0) indicate?

That the two variables increase together.

What does a negative correlation (r < 0) indicate?

That as one variable increases, the other decreases.

What does a correlation close to 0 indicate?

That the variables do not move together linearly.

What assumption does a correlation make about the relationship between variables?

That the relationship follows a straight line.

What hypothesis is supported by a strong positive correlation between relatedness and co-killing?

The fraternal interest groups hypothesis.

What dataset is used to analyze the relationship between age and co-killing?

class-dataset06-pairs-age.csv.

According to Daly and Wilson, what is the expected relationship between age and the number of times people kill together?

A positive relationship.

According to Macfarlan et al., what is the expected relationship between age and the number of times people kill together?

A positive relationship.

What type of relationship did the scatterplot reveal between age and co-killing?

Positive and roughly linear.

What conclusion can be drawn from the small correlation coefficient regarding blood revenge?

It suggests that blood revenge is organized around fraternal interest groups rather than marriage exchange partners.

What is the significance of conducting detective work in hypothesis testing?

To determine which account of social behavior is correct.

What is the main focus of the fraternal interest groups hypothesis?

The organization of blood revenge in society.

What does the term 'marriage exchange hypothesis' refer to?

A competing explanation for social behaviors related to blood revenge.

What is the purpose of cleaning up a scatterplot?

To enhance clarity and understanding of the data presented.

What should be included in a scatterplot to improve its presentation?

Axis titles, appropriate minimum and maximum values, and a linear trend line.

What does the term 'essentially nil' refer to in the context of correlation?

A very weak or negligible correlation between variables.

What is Daly & Wilson's central argument about homicide?

Homicide is a by‑product of ordinary evolved psychological mechanisms, not an adaptation.

Why do Daly & Wilson argue that homicide is not an evolved adaptation?

Killings arise from conflict escalation within systems designed for threat assessment, not from a dedicated mechanism for killing.

What is the "Young Male Syndrome"?

A pattern where young men show heightened aggression and involvement in lethal conflict due to mating competition.

Why is reputation important in Daly & Wilson's explanation of homicide?

Reputation functions as a social resource, and threats to honour can trigger violence to avoid future exploitation.

How does sexual jealousy contribute to homicide?

Sexual jealousy in men can motivate extreme mate‑retention behaviors, including lethal violence.

What does Parental Investment Theory explain about homicide?

Biological parents rarely kill their children, while stepparents are more likely to commit lethal abuse.

What environmental factors influence homicide rates?

Inequality, weak institutions, honour cultures, and unstable social environments increase conflict escalation.

Define "Young Male Syndrome."

A pattern where young men exhibit high aggression and risk‑taking due to competition for status and mates.

Define "Honour/Reputation Logic."

The idea that individuals may use violence to defend status or avoid exploitation in weak legal environments.

Define "Sexual Jealousy."

An emotional response to threats of infidelity, tied to concerns about paternity certainty in men.

Define "Parental Investment Theory."

The principle that parents invest more in offspring who increase their reproductive success.

Define "Self‑Help Justice."

Violence used to settle disputes when formal legal systems are weak or absent.

What does "Homicide as a By‑Product" mean?

Homicide results from normal evolved motives under extreme conditions, not from a specialized adaptation for killing.