- Theories of Emotion
- The Social Behavior Network
Part Of: Game Theory sequence
Content Summary: 1300 words, 13 min read
Prisoner’s Dilemma Review
The classical Prisoner’s Dilemma has following setup:
Two prisoners A and B are interrogated, and separated asked about one another.
- If both prisoners betray the other, each of them serves 2 years in prison
- If A betrays B but B remains silent, A will be set free and B will serve 3 years (and vice versa)
- If both prisoners remain silent, they will only serve 1 year in prison.
We can express the decision structure graphically:
We can also represent the penalty structure. In what follows, arrows represent preference. CC → DC is true because, given that B cooperates, A would prefer the DC outcome (0 years in prison) more than CC (1 year).
Our takeaways from our exploration of the Prisoner’s Dilemma:
The Prisoner’s Dilemma shows us that strategically-dominant outcomes need not be Pareto optimal. Although each arrow points towards the origin for that color, the sum of all arrows points away from the origin.
It packages together the tragedy of the commons, a profound and uncomfortable fact of social living. A person can be incentivized towards an outcome that she, and everybody else, dislikes.
Towards Iterated Prisoner’s Dilemma (IPD)
In the one-off game, mutual defection is the only (economically) rational move. If a person chooses to defect, they will likely receive a bad result.
But consider morwhat happens in a more social setting, where players compete for resources multiple times. An Iterated Prisoner’s Dilemma (IPD) has the following structure:
What strategy is best? Let’s consider two kinds of strategies we might adopt. We can imagine some vindictive prisoners always defecting (AD). Other prisoner’s might be more generous, adopting a Tit-for-Tat (TfT) strategy. This has them initially cooperating, and mirroring their opponent’s previous move.
Let’s imagine that there are 200 “prisoners” playing this game, with each strategy adopted by half of the population. Which strategy should you adopt, in such a scenario?
The games look as follows:
These computations can be generalized to n rounds:
The tit-for-tat (TfT) strategy wins because TfT-TfT games are collaborative, but these players also aren’t effectively exploited by players who Always Defect (AD).
Which Kinds of Strategies Are Best?
There is an very large number of possible IPD strategies. Strategy design might include considerations such as:
Given this behavioral diversity, which kinds of strategy are most successful?
To answer this question, in 1980 Robert Axelrod conducted a famous experiment. He invited hundreds of scholars to enter an IPD tournament, submitting their agent’s decision algorithm digitally. In a computer simulation, every agent played every other agent 200 times. The agent with highest cumulative utility was declared the winner.
Many agent strategies employed quite complex, using hundreds of lines of code. The surprising result was that simple strategies, including Tit-for-Tat, often proved to be superior. Axelrod described three properties shared among successful strategies:
We can call such strategies instances of reciprocal altruism.
Moral and Emotional Implications
The theory of evolution has shown us that biological systems are the product of an optimization process known as natural selection. Only genes that improve reproductive success win over evolutionary time.
From this context, it has long seemed unclear how human beings (and other animals) came to express altruistic behavior. W.D Hamilton’s notion of inclusive fitness explains why we behave generously to relatives. As J.B.S Haldane famously joked,
I would willingly die for two brothers or eight cousins.
Game theory explains our behavior towards non-relatives. Specifically,
IPD provides insight into moral cognition. It shows how our selfish genes might, purely for selfish reasons, come to promote behaviors that are (reciprocally) altruistic.
IPD similarly explains certain emotional processes. For example, I have posited elsewhere the existence of social intuition generators like Fairness. We can now explain why natural selection generated such “socially intelligent” mental modules.
Application: Vampire Bats
Instead of jail time, we can modify our outcome structure to be more relevant to biology.
Thus, we can use game theory to interpret animals competing for resources. Consider, for example, behavior of the vampire bats.
Vampire bats feed on the blood of other mammals. Their energy budget is such that they can tolerate 2 days of food deprivation before starving to death.
On a given night, 8% of adult vampire bats will fail to find food on a given night. But when they do find food, it is often more than they need.
Of course, these animals have a genetic incentive to share blood within family. But you can also observe bats sharing their food with strangers.
How can selfish genes reward altruistic behavior? Because vampire bats are playing IPD:
Towards Evolutionary Game Theory
To show why altruistic bats are more successful? Yes; we need only invent evolutionary game theory (EGT). Recall how natural selection works:
Individuals with more biological fitness tend to leave more copies of their genes.
EGT simply adds this replicator logic to the Iterated Prisoner’s Dilemma (IPD). Players with higher final scores (most resources) leave more descendants in subsequent populations (image credit):
We saw previously that Tit-For-Tat players outperform those who Always Defect. In EGT, this fact establishes how a gene that promotes altruism successfully invaded the vampire bat gene pool:
Of course, iterated games don’t always have one winner. Consider the following food web (structurally similar to Rock-Paper-Scissors, of course).
Snake beats Fox. Fox beats Hawk. Hawk beats snake.
What if the size of the snake population starts out quite small? In that case, hawks and foxes predominate. Since hawks are prey to foxes, the size of the hawk population decreases. But this means the snakes have fewer natural predators.
The above traces the implications of one possible starting point. However, we can use EGT maths to model the entire dynamical system, as follows (image credit):
With this image, we can see that any starting point will eventually (after many generations), lead to a (⅓, ⅓, ⅓) divide of snakes, foxes, and hawks. This point is the locus of the “whirlpool”, it is also known as an attractor, or an evolutionarily stable state (ESS).
Until next time.
Part Of: Demystifying Ethics sequence
Content Summary: 900 words, 9 min read
An ethical theory is an attempt to explain what goodness is: to ground ethics in some feature of the world. We have discussed five such theories, including:
For most behaviors (e.g., theft), both theories agree (in this case, label the act as Evil). But there do exist key scenarios which prompt these theories to disagree. Consider the switch dilemma:
Consider a trolley barreling down a track that will kill five people unless diverted. However, on the other track a single person has been similarly demobilized. Should you pull to lever to divert the trolley?
Our ethical theories produce the following advice:
Would you pull the lever? Good people disagree. However, if you are like most people, you will probably say “yes”.
Things get interesting if we modify the problem as follows. Consider the footbridge dilemma:
Consider a trolley barreling down a track that will kill five people unless diverted. You are standing on a bridge with a fat man. If you push the fat man onto the track, the trolley will derail, sparing the five people.
Notice that the consequences for the action remain the same. Thus, consequentialism says “push the fat man!”, and deontology says “don’t push!”
What about you? Would you push the fat man? Good people disagree; however, most people confess they would not push the fat man off the bridge.
Our contrasting intuitions are quite puzzling. After all, they only thing that’s different between the two cases is how close the violence is: far away (switch) vs up close (shoving).
Towards a Dual-Process Theory
Recall that there are two kinds of ethical theories.
Consequentialism and deontology are prescriptive theories. However, we can also conceive of consequentialism and deontology as descriptive theories. Let’s call these descriptive variants folk consequentialism and folk deontology, respectively.
Sometimes, people’s judgments is better explained by folk consequentialism; other times, folk deontology enjoys more predictive success. We might entertain two hypotheses to explain this divergence:
As we will see, the evidence suggests that the second hypothesis, the dual-process theory of moral judgment, is correct.
Consider the crying baby dilemma:
It’s wartime. You and your fellow villagers are hiding from nearby enemy soldiers in a basement. Your baby starts to cry, and you cover your baby’s mouth to block the sound. If you remove your hand, your baby will cry loudly, and the soldiers will hear. They will find you… and they will kill all of your. If you do not remove your hand, your baby will smother to death. Is it morally acceptable to smother your baby to death in order to save yourself and the other villagers?
Here, people take a long time to answer, and show no consensus in their answers. If the dual-process theory of moral judgment is correct, then we expect the following:
Both predictions turn out to be true. Here then is the circuit diagram of our dual-process, organized in the two cybernetic loops framework:
Four other streams of evidence corroborate our dual-process theory:
Relation To Other Disciplines
We have previously distinguished two kinds of moral machinery:
These machines map to the dual-process theory of judgment. Propriety frames are housed in cerebral cortex, which perform folk consequentialist analysis. Social intuition generators are located within the limbic system, and contribute folk deontology intuitions.
Recall that Kantian deontology attempted to ground moral facts in pure reason (the categorical imperative). While surely valuable as a philosophical exercise, in practice folk deontological judgments have little to do with reason. They are instead driven by autonomic emotional responses. It is folk consequential judgments which depend more on reason (cortical reasoning).
This is not to say that people who prefer consequential reasoning are strictly superior moral judges. But I will address the question which reasoning system should I trust more? on another day.
Until next time.
Part Of: Demystifying Ethics sequence
Content Summary: 1500 words, 15 min
Ethics discussions can occur at different levels of abstraction. The most concrete ethical discussions involve discussing specific topics; e.g., “is abortion moral”? These scenarios are called applied ethics.
Spend enough time wrestling with applied ethics, and you’ll start wondering what all of these moral intuitions have in common. An ethical theory is an answer to the question “what makes a thing good or bad”?
Meta-ethics answers a yet broader set of questions. What is right and wrong, anyways? Are moral beliefs objectively true in the same sense that the Earth orbits the sun? Or is my condemning an unethical act merely expressing an aesthetic preference (“yuck!”)?
Today we conduct a whirlwind tour of ethical theories, touching on the most influential theories. Ethical theories are normative: they speak to what moral conclusions ought to be. However, we will see later how these theories also sometimes imperfectly anticipate the emerging science of moral cognition.
We will discuss the following:
The first three theories are the oldest, and have close ties to religious doctrine. The last two are the most well-known theories these days.
Divine Command Theory
Historically, religions have had a good deal to say about right and wrong. One of the oldest ethical theories is Divine Command Theory, which states:
Moral behaviors are those that are commanded (or willed) by the divine.
This theory was originally proposed in the context of Greek mythology. But since it doesn’t say much about the specific character of the divine, it was adopted by Augustine and some (but not all) modern theologians.
One of the strongest criticisms to Divine Command Theory is the Euthyphro Dilemma, which goes as follows:
Clearly, we must affirm one of these options. But which one? Either “horn” of the dilemma extracts painful concessions:
These days, most philosophers find Divine Command Theory problematic. But there are other ethical theories available to the faithful.
Another approach to ethical theories, championed by Thomas Aquinas, is Natural Law Theory. Moral truths are grounded as follows:
Moral behaviors are those which promote, and do not detract from, a basic good.
A basic good is injected into human nature by God. Here are three such lists, generated by a Catholic, a Muslim, and a philosopher:
Ethical actions promote the basic goods; immoral actions detract from the basic goods. This, incidentally, is why Catholics oppose all forms of birth control: they detract from the basic good of Reproduction.
How did these philosophers generate their lists of basic goods? By observing nature. For example, Life and Reproduction usually make the cut because humans naturally prioritize survival and reproductive success (this is a consequence of natural selection).
However, there is a conceptual difficulty in deriving basic goods from nature. This was clearly expressed by Hume’s Law, also called the is-ought gap: what logical procedure could possibly be used to infer normative statements (an “ought”) from descriptive facts of the words (an “is”)?
Unlike its competitors, virtue theory doesn’t spend much time telling you what to do (moral behaviors). Instead, people are the subject of moral truths. Behaviors are only good or evil insofar as they enhance or corrupt a person’s character.
Aristotle presented these ideas in Nichomachean Ethics. There he describes ethical behavior as a way to achieve eudaimonia (human flourishing or “the good life”).
A life of eudaimonia is a life of striving. It’s a life of pushing yourself to your limits, and finding success. A eudaimonistic life will be full of the happiness that comes from achieving something really difficult, rather than just having it handed to you.
Aristotle also believed that moral knowledge is learned not by navel-gazing, but instead comes from social interactions. Specifically, good character is developed by spending time with virtuous people. This theory is where the idea of a role model comes from.
So let’s get down to business. In virtue theory, moral facts are grounded as follows:
Moral people are those who have character; that is, they possess basic virtues.
Aristotle identified twelve basic virtues: Courage, Moderation, Flexibility, Cleanliness, Generosity, Ambition, Patience, Truthfulness, Wittiness, Friendliness, Modesty, and Righteous Indignation. A good person nurtures these virtues.
The Golden Mean provides some insight into how these virtues can be refined over time. A person can respond too strongly with a virtue (excess), or too weakly (deficiency). For example, one must not have too much courage, nor too little:
Virtue ethics is surprisingly robust to philosophical criticism. However, one scientific concern has been gaining traction recently. Empirical research in the field of situational psychology increasingly suggests that there is no such thing as character traits.
Make no mistake, seeing vices and virtues in others is a universal human instinct. But there is no guarantee that mental software works correctly (e.g., see how the brain lies to itself about visual experience). And the fact of the matter is, character information contributes zero predictive power over how a person will respond to a given situation.
The first ethical theories that isn’t explicitly theistic, Immanuel Kant’s deontological (“knowledge of what is proper”) system purports to result from pure reason.
Moral behaviors are those which obey the categorical imperative.
For Kant, the categorical imperative is a procedure by which a person can discover the rigid contents of the moral universe. He presents four perspectives that independently arrive at these moral truths; the two most influential of which are:
The categorical imperative promotes a kind of moral absolutism: if actions are right or wrong intrinsically, their moral status is invariant to the consequences of an action. And this inflexibility can produce counterintuitive judgments.
For example, consider a house shielding a Jewish family from the Nazis. If a soldier comes to the door asking about its residents, most of use think it would be morally acceptable to lie. Kant, however, claims that lying is wrong in all situations, even ones such as these.
Deontological theories are invariant to behavioral outcome. But there are many moral situations where outcome seems to matter. Consider the trolley problem, where a trolley is currently barreling down a track and should kill five people unless diverted. However, on the other track one person has been similarly demobilized:
Kant would say that pulling the lever is simply murder. That five people die is regrettable, but their death does not incriminate the person at the switch. If the person does divert the trolley, the guilt of the single person’s death is on his head.
However, most people think that the number of deaths – the consequence of an action – matters. Consequentialist theories make this intuition explicit:
Moral behaviors are those that bring the most good to the most people.
Consequentialist theories vary on how they define “the most good” (personal well-being) and “the most people” (societal well-being).
For example, classical utilitarianism, advocated by Jeremy Bentham and John Stuart Mill, which takes the following stances:
Many people condemn utilitarianism for its hedonism (“don’t immoral behaviors often feel pleasurable?”). However, this criticism loses some of its force when you remember to distinguish higher pleasures (eg., aesthetic experience) versus baser pleasures.
The problem of figuring out societal well-being, how to optimize outcomes for communities, is much more challenging. The repugnant conclusion, aka the mere addition paradox, is a particularly damning criticism. A large society with barely tolerable quality of life (e.g., urban sweat shops) doesn’t feel morally equivalent to happier, smaller societies.
Thus, maximizing total well-being may be problematic. But different problems emerge if we instead optimize against average well-being. To this day, designing aggregation functions to compute societal well-being remains an essentially unsolved problem.
Today, we discussed the following theories:
There exist other theories besides these, of course. For example, Hobbes’ contractualism makes important contributions to the conversation.
To date, no ethical theory has emerged as a clear favorite. A recent survey of professional philosophers reveals considerable support for three of the above theories:
Next time, we will explore whether we should view these normative theories as competitors, or complementary solutions to different concerns. Until then.
Part Of: Demystifying Ethics sequence
Content Summary: 1000 words, 10 min read
Main Article: An Introduction To Propriety Frames
The primate brain contains a diverse set of memory structures. For example, episodic and semantic memory store narratives and facts, respectively.
Propriety frames are a memory format that retains social intuitions. This form of memory permits normative judgments, or which behaviors are appropriate or inappropriate.
Propriety frames are organized by situational context. A Restaurant frame provides the social intuitions for restaurant interactions. Frames are the substrate of rituals.
Frames are organized hierarchically to promote reuse. For example, the Eating frame is relevant in contexts besides restaurant dining.
When a mother instructs her son to not yell in the store, the child installs an update to his Shopping frame. When a family exchanges gossip around a campfire, they are doing so in part to synchronize their propriety frames.
The contents of our social intuitions is not arbitrary. Our environment does not fully determine our moral sense. The brain also possesses innate social intuition generators, which contribute to the contents of social judgments.
As outlined in Moral Foundations theory, there are six such generators: authority, care, loyalty, fairness, autonomy, and sanctity.
People are genetically and environmentally disposed to respond to certain generators more strongly than others. Let social matrices be the emotional intensities elicited by each generator.
People with similar matrices tend to gravitate towards similar political parties. When you measure the social matrices of American citizens, you can see large differences between the social intuitions of Democrats and Republicans.
These differences in social matrices explain much of American politics.
For more information, see Graham et al (2009). Liberals and conservatives rely on different sets of moral foundations.
Generators vs Frames
Main Article: A Dual-Process Theory of Moral Judgment
Two mechanisms contribute to social intuitions: propriety frames, and intuition generators.
Generators are located subcortically, and thus produce intuitions quickly and automatically. Frames are stored in the cortical mantle, and are thus slower, and more amenable to conscious awareness.
As the work of Joshua Greene shows, deontological (rule-based) attitudes are generated rapidly; whereas consequential theories of morality are slower and more vulnerable to distraction. This suggests a relatively straightforward mapping:
Frames and Generators can influence one another, albeit slowly. Moral argumentation can change one’s mind, and these frame updates can percolate down to change one’s social matrices (intuition weights). Call this frame internalization.
Similarly, if one’s private intuitions diverge from a culturally inherited norm, that frame can be updated to be more consistent with one’s personality. Call this frame refinement.
For more information, see Cushman, Young, Greene (2010). Our multi-system moral psychology: Towards a consensus view
Human communities generate emergent networks known as cultural regimes. These emerge as distinct categories of frames and intuition generators.
Language made regime accretion possible. No longer is expertise confined to the skull of the individual. No longer is death a Full Restart button. Our species sends cultural expertise down through the generations. This knowledge – these frames – have become increasingly sophisticated over the course of human history.
Hominid evolution has also seen the advent of regime diversification. Modern religions (of the Axial Age) were successful because they improved on our ability to trust strangers. This in turn dramatically increased the size of feasible social groups.
We have so far only been speaking about social attitudes (should / should not). What about moral attitudes (good / evil)?
Moral attitudes are nothing more than a kind of social attitude. I know of no moral attitude that can be divorced from a social context.
Moral attitudes are constructed by moral tagging, which endows a subset of social attitudes with anger and disgust reactions (as opposed to the more typical reputation appraisal, gossiping, shaming).
Further, moral tagging produces appraisal inflexibility. Moral violations are viewed as wrong everywhere, in every context. This is in contrast to other social violations, for which it is easier to see circumstances in which the behavior would seem less bad.
The boundary between Virtuous and Tolerable is smooth, reflecting the flexibility of our intuition generators. In contrast, the boundary between Tolerable and Intolerable is sharp.
A similar distinction appears amidst disagreement. There are two kinds of ways people’s judgments can diverge:
For more information, see Tetlock et al (2000). The psychology of the unthinkable: taboo trade-offs, forbidden base rates, and heretical counterfactuals.
The space of possible social intuitions is vast. However, group living only became possible with relatively homogenous norms. How do individual brains synchronize propriety frames and social matrices within a group?
At least four mechanisms provide norm synchronization.
This sequence is simply a bucket that collects some of my older, “pre-theoretic” views on psychology. YMMV. 🙂
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