Sociology: An Analytical Core Herbert Gintis Santa Fe Institute July 2013

Summary Economics and biology each has a common core of analytical theory that all practitioners learn as a common basis for discourse, testing, and revision. Sociology lacks such a common core. Rather, every sociological theorist develops a grand intellectual structure that rejects rather than building on past theoretical successes. For this reason, sociological theory is widely ignored by the other behavioral disciplines, leading to the exclusion of sociology from the current move towards the unification of the behavioral sciences.

Summary We must build an analytical core to sociological theory. What follows is my concept of what such a core should include.

Summary 1. Sociobiology: The place of humans in the array of social species The Major Transitions in Evolution: Cumulative Increase in the Complexity of Social Interaction Every major transition involved a solution to a complex social dilemma Gene-Culture Coevolution in Humans 2. Rational Choice: The Role of Morality and Prosociality in Rational Choice Networked Minds and Distributed Cognition Self-regard, other-regard, and character virtues

Summary 3. Social Structure Social Actor and Social Role The Articulation of Social Roles Social Frames 4. Integration of Social Actor and Social Structure Social Production of Common Priors The Socio-psychological Theory of Norms Game Theory: The Correlated Equilibrium and the Choreographer Social norms are correlated equilibria

The Sociobiology of Dictyostelium Discoideum Dictyostelium Discoideum is a cellular slime mold. When food is readily available it lives as an individual amoeba, feeding and dividing normally. When food is exhausted, individuals aggregate to form a multicellular assembly, called a slug. The slug forms a fruiting body with a stalk supporting a ball of spores. These spores remain dormant until food is available. The stalk is composed of individual amoebae which die during stalk formation.

Dictyostelium Discoideum

Dictyostelium Discoideum is a beautiful example of a social dilemma. The future of the group depends on cooperating in forming the stalk and choosing some individuals to live as spores while the rest die as members of the stalk. How cheating is limited in Discoideum and other such species is complex and only partially understood.

The Major Transitions in Evolution Prokaryote  Eukaryote Union of previously independently-living prokaryotes into a complex cooperative unity. Clones  Sexual reproduction Mendelian (fair) segregation is the product of gene regulatory networks that prevent cheating. Tensions remain; e.g., mitochondria have their own non-Mendelian (maternal) inheritance system.

The Major Transitions in Evolution Single-cell protists  Multicellular organisms Which cells get to reproduce? How to avoid cheaters who benefit from the cellular division of labor without contributing? Solitary individuals  Societies of interaction individuals How to prevent defectors from reducing fitness. How to promote non-reproductive castes, such as workers and soldiers in an insect colony. Genetic control of behavior  Gene-culture coevolution How to control defectors in a totipotent species (i.e., where all individuals reproduce).

The Genetic Contribution to Behavior Genes Environment Behavior Culture Genes predispose individuals to behave in certain ways, and provide them with the capacity to do so. For instance, human infants are predisposed to share, and have a sophisticated theory of mind.

The Central Problem of Sociobiology in Humans Human sociobiology is the study of the interaction among utterly selfish genes, the human core genome, which promotes cooperation through the action of regulatory gene networks, and culture/institutions.

William Hamilton: The Father of Sociobiology William Hamilton ( ) noticed that a gene that leads its carriers to sacrifice personal fitness for others will increase in the population if there are a sufficient number of copies of the gene in the beneficiaries. However, the same argument shows that a gene that reduces the fitness of individuals lacking the gene will also be evolutionarily successful. Conclusion: the success of individual genes does not depend on their effect on the fitness of their carriers! This is why we say genes are utterly selfish.

The Selfish Gene William Hamilton’s inclusive fitness theory is a straightforward extension of the basic principles of modern population biology, and covers both intergenomic (social) and intragenomic (biochemical) interactions at a single genetic locus. It cannot be wrong unless all of modern population biology is wrong. This fully supports the concept of the selfish gene developed by George Williams (1966) and Richard Dawkins (1976).

The Selfish Gene We are survival machines – robot vehicles blindly programmed to preserve the selfish molecules known as genes. This is a truth which still fills me with astonishment. Richard Dawkins, The Selfish Gene (1976) I would drop the “robot,” because we are obviously not robots (were Goethe, Shakespeare, and Einstein robots?). but the rest is astonishingly true.

The Selfish Gene Dawkins interpreted the fact that genes are utterly selfish as implying that all creatures must be behaviorally selfish: Let us try to teach generosity and altruism, because we are born selfish. Richard Dawkins, The Selfish Gene (1976) This conclusion is at odds with the evidence we have on human behavior, coming from developmental psychology laboratory and field studies.

A Cooperative Species with Samuel Bowles Princeton University Press 2010

Other Cooperative Species Studies show that non-human primates also exhibit extensive prosocial behaviors if, like humans in the hunter-gatherer stage of evolution, they engage in collective child-rearing. The centrality of collective child-rearing in other species suggest that human sociology should stress the structure of child care very carefully.

Gene-culture Coevolution Individual fitness in humans depends on the structure of social life. Human cognitive, affective, and moral capacities are the product of an evolutionary dynamic involving the interaction of genes and culture. For a more complete analysis and extensive references, see Herbert Gintis, "Gene-culture Coevolution and the Nature of Human Sociality", Proceedings of the Royal Society B 366 (2011).

Gene-culture Coevolution In this dynamic, humans transform culture, and the new cultural environment alters the nature of fitness-enhancing genes. Thus, genes are the product of culture just as culture is the product of genes.

Gene-culture Coevolution I will give a dramatic example of gene-culture coevolution: the evolution of the physiology of speech and facial communication. The increased social importance of speech in our hominin ancestors rewards genetic changes that facilitate speech. Regions in the motor cortex expanded in early humans to facilitate speech production. Concurrently, nerves and muscles to the mouth, larynx, and tongue became more numerous to handle the complexities of speech.

Gene-culture Coevolution Adult modern humans have a larynx low in the throat, a position that allows the throat to serve as a resonating chamber capable of a great number of sounds. In addition, the production of consonants requires a short oral cavity, whereas our nearest primate relatives have much too long an oral cavity for this purpose.

Gene-culture Coevolution Another indication that the tongue has evolved in hominids to facilitate speech is the size of the hypoglossal canal, an aperture that permits the hypoglossal nerve to reach the tongue muscles. This aperture is much larger in Neanderthals and humans than in early hominids and non-human primates (Campbell 2000). Human facial nerves and musculature have also evolved to facilitate communication.

Gene-culture Coevolution I have illustrated gene-culture coevolution by the evolution of communication physiology. But gene-culture coevolution applies to the emergence of unique human emotional capacities (e.g., shame, guilt, pride, empathy, jealousy, and a taste for retribution). This coevolutionary process has endowed us with preferences that go beyond the self-regarding concerns emphasized in traditional economic and biological theory

Gene-culture Coevolution Gene-culture coevolution explains why we have a social epistemology facilitating the sharing of intentionality across minds, as well as why we have such non-self-regarding values as a taste for cooperation, fairness, and retribution, for the capacity to empathize, and for the ability to value character virtues (e.g., honesty)

The Rational Actor Model Behavioral game theory, like much of economic theory, is built on the rational actor model, which treats choice as taking the most preferred among a set of alternatives. This model is extremely general, requiring only consistency of preferences. It applies to the heuristics described by Gigerenzer when the issue is choice rather than problem solving. The model applies to bacteria just as well as to humans. When choice is over risky alternatives, the theory implies that agents have subjective priors: probability distributions over the various outcomes. Rational agents maximize expected utility subject to their subjective priors.

The Rational Actor Model The rational actor model is widely criticized outside of economics and biology, but these critiques are generally based on attributing to the theory assertions that are in fact not part of the theory or desirata that are easily incorporated in the theory. The results of Kahneman, Tversky et al. are often cited as violations of the rational actor model, but in fact they generally are not (Gintis, Bounds of Reason, 2009). Indeed, prospect theory, for which Kahneman was awarded the Nobel prize in Economics, is based on the rational actor model. Behavioral game theory without the rational actor model has no coherence.

The Rational Actor Model There is, however, one deep problem with the rational actor model: it assumes that agents choose in isolation from other agents. In fact, human have networked minds supporting distributed cognition. Sociology should aim towards characterizing the structure and dynamics of networked minds and how cognition is shared across minds. I have explored this using agent-based models where networks of individuals control the replicator dynamic.

Networked Minds, Distributed Cognition Networked minds with distributed cognition in humans is the product of gene-culture coevolution (Robin M. Dunbar et al., Social Brain, Distributed Mind, 2010). Modeling distributed cognition is difficult, but it is aided by game theory and the rational actor model.

Defending Rational Choice Rational choice theory does not require that the choices people make be welfare-improving. In fact, people are often slaves to such passions as smoking cigarettes, eating junk food, and engaging in unsafe sex. These behaviors do not violate preference consistency, and hence are rational, according to the rational choice model’s “thin” conception of rationality.

Defending Rational Choice Rational choice does not require that rational actors be good problem-solvers. If humans cannot solve complicated problems, like evaluating the expected value of a lottery, they may simply not know how. Assuming that rational actors can solve complex problems is a failure of social theory, not the rationality assumption.

Defending Rational Choice Most important, rational choice does not imply self- interested choice. It is rational to care for others, believe in fairness, or sacrifice for a social ideal. Indeed, Andreoni and Miller (2002) have shown that people obey all the usual principles of rational choice in the case of contributions to charity.

Defending Rational Choice Suppose a man with $100 is considering how much to consume himself and how much to give to charity. Suppose he faces a tax or subsidy such that for each $1 he contributes to charity, he is obliged to pay p dollars. Thus, p > 1 represents a tax, while 0 < p < 1 represents a subsidy.

Defending Rational Choice We can then treat p as the price of a unit contribution to charity and model the individual as maximizing his utility for personal consumption x and contributions to charity y, say u(x,y) subject to the budget constraint x + p y = 100. It is perfectly rational for him to choose y > 0. Indeed, in making choices of this type, consumers behave in the same way as they do when choosing among personal consumption goods; i.e., they satisfy the generalized axiom of revealed preference (GARP).

Character Virtues Character virtues are ethically desirable behaviors that individuals value for their own sake. The character virtues include honesty, loyalty, trustworthiness, fairness, considerateness, etc. These character virtues operate without concern for the individuals with whom one interacts: one is honest because it is the right way to behave. Character virtues are not absolutes. If the cost of honesty is sufficiently high, most individuals will behave dishonestly (Gneezy 2005).

Honesty In Gneezy (2005), subjects pair off, and the first of the pair, Bob, is shown two options. Option A, pays 5 to Bob and 6 to his partner Alice. Option B reverses the payoffs. Bob sees the payoffs to the two options but Alice does not. Alice chooses the option, after hearing Bob’s advice (which she was free to ignore). Alice is told that one of the options is better for Bob, and the other is better for her.

Honesty Bob is permitted to send either of the following two messages to Alice: “Option A will earn you more money than option B” or “Option B will earn you more money than option A.” Gneezy found that 83% of Bobs told the truth. and 78% of Alices believed Bob’s message. As the cost to Bob of being honest increases, the probability that Bob will lie goes up as well.

The Sociological Actor The individual is a rational actor with a preference function that includes self-regarding and other- regarding objects of desire, as well as valuing virtuous behavior. The belief system of the actor is constituted from the position of the individual in one or more distributed networks of minds, and depends on the distribution of information across these networks.

Social Structure: Role-based Social Division of Labor The social division of labor consists of actors filling social roles (George Herbert Mead, Ralph Linton). Attached to a social role is a content, consisting of a set of rights, duties, expectations, material and symbolic rewards, and behavioral norms. In social equilibrium, the content of social roles is common knowledge; i.e., all know and agree on the content of social roles. Ascriptive states (e.g., man, woman, Korean, accident victim, prisoner) are not social roles.

Social Structure: Role-based Social Division of Labor An actor’s behavior in a social role can be modeled as the maximization of his objective function subject to the content of the role. Few social roles can be productively filled without drawing on the moral commitment of role- occupants.

Social Structure: Role-based Social Division of Labor Economic theory has attempted to model role performance as motivated by pure self-regard, but this has failed because complete contracts are unfeasibly costly to enforce, and because principals (government, supervisors) have incomplete information concerning performance in complex economic roles. Contracts based on a strong element of trust are superior to complete (but unenforceable) contracts. See, for instance, Brown, Falk, and Fehr, Econometrica 2004.

Social Structure: Role-based Social Division of Labor When social roles are not strongly legitimated, role-performance will deteriorate. Often this is called corruption. Similarly, if unethical role-performance is not appropriately socially sanctioned, social cooperation will generally unravel, leading to widespread non-compliance.

Social Structure: Social Frames How does an actor know what role he currently occupies? Every social situation has a social frame that supplies the sensory cues as to the social situation in which the individual is situated, and the particular social role the individual occupies in this social situation. In equilibrium, the set of social frames is common knowledge. Definition: A state s is common knowledge if all actors know s, all actors know that all actors know s, all actors know that all actors know that s, and so on, to whatever depth of recursive knowledge is required.

Common Knowledge is Durkheim’s Collective Representations Common knowledge is Durkheim’s notion of collective representations, shorn of its possible metaphysical dimensions. “Collective representations exist outside of individual consciences…they derive not from individuals taken one by one, but from their interaction.” Émile Durkheim Sociologie et Philosophie

Common Knowledge is Durkheim’s Collective Representations A central unifying task of social institutions is to turn private information into common knowledge as a basis for an efficient social division of labor.

Epistemic Game Theory The concept of common knowledge comes from epistemic game theory. See: The Bounds of Reason (Princeton 2009).

Example: The Role of Voter In Liberal Democracy The electoral process in a liberal democracy is perhaps the grandest example of a social dilemma. The legitimacy of liberal democracy depends on a high level of electoral participation. However, individual voters have no self-regarding interest in voting because one vote makes no difference in a large election. No voter has a self-regarding interest in voting his self-interest. Therefore the electorate has no self-regarding interest in being politically informed. The electoral process is a vast morality play.

The Socio-psychological Theory of Norms The socio-psychological theory of norms relates social morality to individual morality. Social norms are commonly seen as devices that choose among the Nash equilibria of an underlying social role-playing game. In fact, social norms are better explained as correlating devices for an underlying stage game.

The Socio-psychological Theory of Norms The epistemological requirements for Nash equilibrium are very stringent and usually implausible, but the requirements for a correlated equilibrium are simply the existence of common priors, which we interpret as induced by the cultural system of the society in question. Common priors are common knowledge of the rules of the game, which are Durkheim’s collective representations. I call the system that creates common priors the choreographer to stress its socially constructed role in promoting cooperation among disparate actors with distinct interests.

The Socio-psychological Theory of Norms Social norms are an emergent property of human society, In particular, social norms are predicated upon a social epistemology, instantiated in the neural structure of the human brain, that is the product of individual ontogeny (personal development) and our common species phylogeny (natural selection and adaptation).

The Socio-psychological Theory of Norms This social epistemology fosters the interpersonal sharing of mental concepts, and justifies the assumption of common priors upon which the identification of Bayesian rationality with correlated equilibrium rests.

Epistemic Conditions for Correlated Equilibrium