Book: A Cooperative Species (Bowles & Gintis, 2011)

Started reading after re-reading the preface of Book: The Moral Economy, which outlines Sam Bowles' trajectory as first working on establishing prosocial motivations as important, before turning to their interactions with self-interest driven behavior.
== Summary ==
Ch1 is kinda the intro, Ch2 an overview of definitions/terminology, and from there subchapter 2.4 previews the rest of the book:
Preview form 2.4: Ch3: Q statement, Ch4,5: existing possible but inadequate answers, Ch6-11: proposed alternative explanation, Ch10-11: move from evo processes that explain cooperation to proximate motives for cooperation.
* Ch3: consider evidence of social preferences—e.g. voluntary cooperation in one-shot interactions—that pose the evolutionary puzzle for the remainder of the book: how did humans come to have these social preferences?While this puzzle is very interesting, for myself I think I'm more interested in models of the mechanics/dynamics of social preferences and choice. How do they regulate behavior and constitute (a) governing mechanism(s) in society?
* Ch4: review common approaches in biology to explain cooperation, and models of repeated interactions and possibility of reputation building.
* Ch5: ask if recent advances in theory of repeated games (folk thm and related models) address the shortcomings of self-interest based models. Find that both models from ch4 and ch5 are inadequate [in what sense?]
* Ch6: group competition in early human societies could have proliferated altruistic behaviors, by conferring fitness benefits.
* Ch7: explains how group competition favored coevolution of hunter-gatherer society institutions along with predispositions for altruistic behaviors
* Ch8: study how intergroup hostility could have proliferated group competition processes essential to the evolution of altruistic cooperation.
* Ch9: explains how the punishment of exploitation of group members could have initially emerged and proliferated
* Ch10: study deliberate socialization to internalize group norms, how this capacity for internalization could have evolved and why the norms internalized tend to be group-beneficial.
* Ch11: study the role of social emotions (guilt, shame) in supporting cooperation and how they might have evolved.
* Ch12: conclusion: review of proposed explanations and looking further/forward.
=== Ch 1. A Cooperative Species ===
How can Homo sapiens have come to be such a cooperative animal? They advance two propositions:
# [proximate motivations for prosocial behavior] People don't cooperate just for selfish reasons. They have other motivations for prosocial behavior: genuine concern for others, upholding social norms, morality, and feelings of shame/guilt.
# [evolutionary origins of these cooperative dispositions] These 'moral sentiments' proliferated from the survival and reproduction/expansion dynamics present among our ancestors.
They give some examples of cooperation being commonplace among our ancestors (esp. hunting) and other primates. But, note that human cooperation is exceptional in that it extends to a much larger scale (not just family, but also to total strangers).They caveat this, noting that social insects also cooperate on such a scale. Goal of the book is to examine cultural, biological, and other processes that explain how humans became exceptionally cooperative species. 
Start by defining two types of cooperation: "engaging with others in a mutually beneficial activity". But as they define it, not necessarily net beneficial to each, which forms the distinction between: 
* Mutualism: a type of cooperative behavior that confers net benefits on both the actor and on others
* Altruism: a type of cooperative behavior that imposes net costs upon individuals, not cooperating would increase their fitness or material payoffs
Notes that cooperation that is (1) mutualistic or (2) involves only close family relatives can be easily explained.They don't further explain (1), but I assume its just some type of individually rational behavior. (2) can be explained by: (a) natural selection, which would mean some type of survival/reproduction benefit that helps proliferate alleles/'genes' associated with cooperative behavior, or (b) reciprocal altruism, where one's costly action is reliably reciprocated, which makes it mutualistic.Which they note should really be called "enlightened self-interest". Does this really answer it? Requires that the costly action + receipt of benefit > 0. Also, why doesn't it unravel?
These models [(a), and (b)?] fail to explain two facts about human cooperation:
# That cooperation takes place in groups far larger than the family
# That it occurs in interactions that are unlikely to be repeated and reputational gains are impossible.
They note that the most parsimonious explanation of cooperation (supported by extensive evidence) is that people have social preferences: "a concern—positive or negative—for the well-being of others, and a desire to uphold ethical norms". Hence, the task of the book is not to explain why people cooperate despite being selfish (as economists/biologists typically try), but to explain why we are not purely selfish—how social preferences that sustain altruistic cooperation are so common.
In the book, they advance three reasons why altruistic social preferences that support cooperation outcompeted pure self-interest:
# Human groups devised ways to protect altruistic members from exploitation by self-interested ones
# Humans adopted elaborate systems of socialization that led people to internalize norms that support cooperation, so that cooperation became an objective in its own right
# Between-group competition is a decisive force in evolutionary dynamics, and cooperative groups were more competitive
However, they note that the regulation through group-level institutions plays no less a role than altruistic individual motives in the evolution of our cooperative species.
They point out that cooperation is not an end, but a means, and so is competition. Depending on the setting, either one may be more effective. Given the extensive body of experimental evidence on social preferences, the question is not how it is possible that 'tragedy of the commons' or 'prisoner dilemma' situations are avoided in practical situations. Instead, the puzzle is how humans came to be like this.
=== Ch 2. The Evolution of Altruism in Humans (8-18) ===
Terminology:
* Helping: behaviors that confer benefits on others
* Altruism: Two definitions:
*# Biological definition: helping in situations where the helper would benefit in fitness or material ways by withholding help. (they say this is outcome-based)
*# Preference-based definition: altruistic preferences place positive value on the beneficial outcomes of one's actions for others. (they say this is intention-based)
* Constraints: limitations placed on feasible actions an individual may take in a given situation
* Beliefs: an individuals' representation of the causal structure of the world, including the relationship between their actions and the probabilities of possible resulting outcomes
* Preferences: the pro or con sentiments that make up an individual's valuation of the various possible outcomes of taking an action
* Self-Interest Axiom: people seek to maximize their expected payoffs and believe other do the same
* Social Preferences: a concern for the well-being of others and a desire to uphold ethical normsSocial preferences include things like conspicuous consumption, pecuniary emulation, etc. They may be self-regarding.
* Self-regarding preferences: those based on states concerning oneself aloneIn other words, independent of the states other people experience
* Other-regarding preferences: valuations based at least in part on states that occur to others
* Ethical preferences: may reflect a concern for the states experienced by others, but need notSo these are different from other-regarding preferences, which must reflect a concern for the states others experience?
* Social dilemmas: interactions where the uncoordinated actions of individuals result in Pareto inefficient outcomes (e.g. prisoner's dilemma, tragedy of the commons, etc.)
* Non-cooperative game: binding agreements are not possible
* Culture: the ensemble of preferences and beliefs that are acquired by means other than genetic transmissionsee note in p.13. It's probably fine to be overly inclusive rather than restrictive in definition, but this seems to include in culture some beliefs about 'how the world works' that are derived from experience but don't feel like 'culture'. E.g. I believe the sun will set tonight and rise again today. Is that culture?. Cultural transmission = social learning != individual learning. Takes the form of vertical (parents -> children), horizontal (peer -> peer), oblique (non-parent elder -> younger) transfers of information.
*
Intro: the traditions in biology and social sciences (from Dawkins to the folk theorem in game theory) that seeks to explain cooperative behavior by "the principle of self-interest", has clarified ways in which helping close family members, or repeated interactions and reputation-building, might confer advantages on those engaging in seemingly unselfish behavior. They favor a different approach: the gene-culture coevolution.
==== 2.1 Preferences, Beliefs, and Constraints ====
They start by setting out what explains individual action in the beliefs, preferences, and constraints approach, common to econ and decision theory.
* Constraints: the limitations placed on the feasible actions an individual may take in a given situation
* Beliefs: an individual's representation of the causal structure of the world, including the mapping from their actions to the probabilities of various possible resulting outcomes
* Preferences: the pro or con sentiments that define one's valuation of the set of possible outcomes from an action. They assume preferences are complete and transitive. In addition, they note preferences are the results of a variety of influences, thus exogenous!Afaict, this is the innovation they make: they keep the fundamental model of preferences, beliefs, and constraints, but open up preferences to be exogenous. So, instead of only caring about your own material interests, you may be conditions with certain tastes, have morals, internalized social norms, susceptible to norm-based pressure, etc.
They note we can analyze behavior as maximizing a preference function, even though this by no means describes the underlying psychological processes, just that this framework may provide a concise and accurate account of actions.Should finish reading Book Ch: The Methodology of Positive Economics, Friedman (1953), and think about how this compares. Hence, it is silent on the cognitive and other processes determining action, e.g. use of rules of thumb, or actual calculation. 
A standard version of the preferences, beliefs, and constraints framework incorporates behavioral assumptions summarized as Homo Economicus. Note however, that preferences don't need to be defined as self-interested, they could be altruistic or even masochistic. The self-interest axiom is not to be taken literally—there are numerous examples of how it fails to explain people's behavior.E.g. see List of Behaviors Not Explained by Self-Interest.
==== 2.2 Social Preferences and Social Dilemmas ====
[I asked Sam: it still isn't 100% clear to me what he has in mind here, but: he said there are basically two types of preferences: self-regarding and other-regarding. My guess is there's something about directly caring about the states experienced by others (other-regarding) versus e.g. rule-driven ethics (Sam for a second mentioned behavior driven by virtue ethics), which makes you invested in other people's outcomes but in an entirely self-regarding manner. E.g. being honest because that's the type of person one wants to be.]
* Social preferences: a concern for the well-being of others and a desire to uphold ethical norms
* Self-regarding preferences: based on states concerning oneself alone
* Other-regarding preferences: valuations based at least in part on states that occur to others
* Social preferences may be self-regarding. 
* Social dilemma: interactions in which the uncoordinated actions of individuals result in a Pareto inefficient outcome
* Free riding: if one person benefits from the contributions of other group members while themselves contributing less or nothing
==== 2.3 Genes, Culture, Groups, and Institutions ====
Culture: the ensemble of preferences and beliefs that are acquired by means other than genetic transmission.What about beliefs that are derived from experience in the world? E.g. I believe the sun will set tonight and rise again tomorrow. Is that cultural? Seems like there is a set of beliefs about how the world works that is non-cultural. Or is this 'universal culture'? That feels like an oxymoron. 
One—they think incorrect—approach holds that while preferences and beliefs that are transmitted culturally may constitute the proximate causes of behavior, they are themselves entirely explained by genetics and the natural environment. While this channel of causality is certainly important, they note that culture also affects the relative fitness differentials of genetically transmitted behavioral traits. They prefer an approach which was developed in the 1970s of gene-culture coevolution: that human preferences and beliefs are the product of a dynamic whereby genes affect cultural evolution, and culture affects genetic evolution, the two being tightly intertwined in the evolution of our species.
gene-culture coevolution, their approach: 
# They don't think 'genes for cooperation' are likely to exist, so their genetic transmission reasoning operates at the phenotypic level.
# In their models of selection, higher payoff (in e.g. fitness, material reward, social standing, etc.) behaviors tend to increase in frequency in the population.
# Positive feedback loops may lead to multiple equilibria when initial conditions vary. The equilibrium outcome need not be globally optimal, just locally. Hence, equilibrium selection is of major importance.
# The dynamics of the set of existing groups, their institutions, their boundaries, and their conflicts are essential components of the co-evolutionary process.
# Chance/stochastic factors play an important role in human evolution.
# A model of the evolution of human cooperation must hinge on empirical evidence. The question is not 'which model works?', since they all work if mathematical coherence is the bar. 
==== 2.4 Preview ====
See beginning of summary; overview of ch3-12/rest of book.
=== Ch 3. Social Preferences ===
In this Ch: show evidence that even in non-repeated interactions, many people willingly cooperate with strangers even at a cost to themselves. They also enthusiastically punish shirkers who see to exploit cooperators. For example, in the ultimatum game, most proposers offer between 40-50%, and responders frequently reject offers below 25%. This poses the evolutionary question for the rest of the book: how did humans come to have these social preferences?
==== 3.1 Strong Reciprocity is Common ====
Strong reciprocity: preferences that motivate people to sacrifice their own payoffs in order to: cooperate with others, reward them for cooperation, and punish free-riders. 'Strong' distinguishes these preferences from self-regarding reciprocation that would not be undertaken if it didn't pay off—people with strong reciprocity preferences would increase their payoffs by not cooperating. These are altruistic preferences by the biological definition. Behavior that would follow from such preferences is common.
* E.g. in a one-shot prisoner's dilemma (payoffs C_i: {b-c, -c}, D_i: {b, 0}) where self-regarding individuals would mutually defect, a higher level of cooperation occurs when people know that their partner has already cooperated, or if they know their own decision will be communicated to their partner prior to the partner's choice. Hence, knowing that your partner cooperates changes the subjectively relevant payoffs in the game. 
* Fehr et al. (1997) 'experimental labor market' is a version of the gift exchange game. Here, they employ a worker at a specified wage-effort 'contract' (w,e^*)who in turn choses unobservable effort. A selfish employee would choose the zero-cost effort level no matter what. However, this outcome rarely occurred in the experiment: higher demanded effort corresponded to higher wages and higher exerted effort—workers cooperated at a cost to themselves. To check if employers were also strong reciprocators, they added a version where employers could observe effort and reward or punish at a cost. In ~70% of cases, employers punished workers who did not fulfill their contracts, and rewarded ones who overfilled them. Moreover, employees expected this behavior, as underfilled contracts dropped from 86% to 26% and overfilled ones from 3% to 38%.
==== 3.2 Free-Riders Undermine Cooperation ====
In social dilemma's that are repeated, subjects tend to start with significant levels of cooperation, which decays to a very low level over the rounds unless there are very few free-riders.
* Public goods game/n-person prisoner's dilemma example: 10 people each can contribute up to $1 to the common pool, which has a 400% return and in divided amongst all 10 people (so each person gets $0.50 for a $1 common pool contribution). There are 10 such rounds. As in a prisoner's dilemma, dominant strategy is to contribute nothing.Why? This depends on the strategies of others, no? If their future contributions depend on your current contribution, you might have an incentive to contribute? In practice, people start by contributing 50-70%, and this decays to almost zero in later rounds. 
* The interpretation for this is that people want to retaliate against free-riders, as even if people play multiple sets of rounds, the same pattern occurs. Hence, not based on people learning about the effects of their actions.
* Another study (Page et al. 2005) lets people play a set of rounds three times before sharing their contributions data with everyone and allowing people to match with each other for another set of rounds. This leads to high-contribution people to play with each other, resulting in average contribution rates of over 90% with no decay: when those predisposed to cooperate can associate with each other, cooperation is not difficult to sustain!
==== 3.3 Altruistic Punishment Sustains Cooperation ====
In social dilemmas, strong reciprocators willingly punish free-riders, which induces cooperation and allows it to be sustained over time. Many examples, they highlight:
* Fehr & Gachter (2000, 2002): public goods game in 4-person groups, where punishment at cost is possible in the first 10 rounds, and removed in the last 10 rounds. Three different group-assignment methods: partner treatment (remain in same group), stranger (randomly assigned to group each round), and perfect stranger (randomly assigned but to others you haven't played with before). In the partner treatment, almost full cooperation was reached with no decay until the option for punishment was removed (same patterns in other treatments but lower level). 
* They note: people have an intrinsic desire to punish shirkers, like the negative analogue of Andreoni (1990)'s warm glow altruism. This desire for retribution is confirmed by Falk et al (2005) and Fudenberg & Pathak (2010). 
==== 3.4 Effective Punishment Depends on Legitimacy ====
=== Ch 4. The Sociobiology of Human Cooperation ===
=== Ch 5. Cooperative Homo Economicus ===
=== Ch 6. Ancestral Human Society ===
=== Ch 7. The Coevolution of Institutions and Behaviors ===
=== Ch 8. Parochialism, Altruism, and War ===
=== Ch 9. The Evolution of Strong Reciprocity ===
=== Ch 10. Socialization ===
=== Ch 11. Social Emotions ===
=== Ch 12. Conclusion: Human Cooperation and its Evolution ===
== Gene/Biology terms ==
* Phenotype: term from genetics; the set of observable characteristics or traits of an organism. An organism's phenotype results from two basic factors: the expression of an organism's genetic code (its genotype) and the influence of environmental factors.
* Epigenetics: the study of heritable traits, or a stable change of cell function, without changes to the DNA sequence. ('epi-', meaning 'over, outside, or around'). Usually involves a change not erased by cell division, and affects the regulation of gene expression.