Robin Hanson

Are you fascinated by some basic questions about science, technology, and our future? Questions like: Is cryonics technically feasible? When will nanoassemblers be feasible and how quickly will resulting changes come? Does a larger population help or hinder the world environment and economy? Will uploading be possible, and if so when? When can I live in space? Where will I be able to live free from tyranny? When will A.I.s be bucking for my job? Is there intelligent life beyond earth? If you are like most Extropy readers, such question matter to you. Now how do we, as a society, go about answering such questions? People who have an appropriate background, and who are interested enough in a particular question, can research that subject in depth themselves, and come to a considered opinion. And people who happen to know, respect, and trust such a person can simply take those opinions as their own, avoiding all the hard work. But what is everyone else to do, people whose actions often implicitly depend on such questions? In practice, people usually defer to larger social institutions on most questions, institutions which combine and evaluate contributions from many specialists, and which offer apparent institutional consensus estimates on many different questions.

We are economists with a long-standing interest in evolutionary psychology, who recently came to appreciate the rich collections of relevant data cultural anthropologists have spent decades collecting on the social environments of a wide range of human societies. While we found some systematic collections of these observations, we could not find a systematic summary of the social environment of the subsample of societies that most resemble the social environment where most human psychology seems to have evolved: small bands of nomadic foragers. This short paper therefore represents our attempt to create such a summary. Using an existing dataset aggregated from diverse ethnographies, we collect statistics on the social environment of the studied cultures which most closely resemble our hunter-gatherer ancestors. Compared with relatively modern societies, nomadic foragers had similar levels of food and disease, and less murder and suicide. They did not fight over land or resources, and they enforced justice directly and personally. They avoided class divisions like rich vs. poor, shared food more, and their leaders had no formal powers. Polygamy, premarital sex, and extramarital sex were all widespread, divorce was easy, and men and women were generally considered equal. Kids were taught to be more generous, trusting, and honest, and were never punished physically.

In standard belief models, priors are always common knowledge. This prevents such models from representing agents’ probabilistic beliefs about the origins of their priors. By embedding standard models in a larger standard model, however, pre-priors can describe such beliefs. When an agent’s prior and pre-prior are mutually consistent, he must believe that his prior would only have been different in situations where relevant event chances were different, but that variations in other agents’ priors are otherwise completely unrelated to which events are how likely. Due to this, Bayesians who agree enough about the origins of their priors must have the same priors

Consider two agents who want to be Bayesians with a common prior, but who cannot due to computational limitations. If these agents agree that their estimates are consistent with certain easy-to-compute consistency constraints, then they can agree to disagree about any random variable only if they also agree to disagree, to a similar degree and in a stronger sense, about an average error. Yet average error is a state-independent random variable, and one agent's estimate of it is also agreed to be state-independent. Thus suggests that disagreements are not fundamentally due to differing information about the state of the world

In Everett's many worlds interpretation, quantum measurements are considered to be decoherence events. If so, then inexact decoherence may allow large worlds to mangle the memory of observers in small worlds, creating a cutoff in observable world size. Smaller world are mangled and so not observed. If this cutoff is much closer to the median measure size than to the median world size, the distribution of outcomes seen in unmangled worlds follows the Born rule. Thus deviations from exact decoherence can allow the Born rule to be derived via world counting, with a finite number of worlds and no new fundamental physics

Policy disputes arise at all scales of governance: in clubs, non-profits, firms, nations, and alliances of nations. Both the means and ends of policy are disputed. While many, perhaps most, policy disputes arise from conflicting ends, important disputes also arise from differing beliefs on how to achieve shared ends. In fact, according to many experts in economics and development, governments often choose policies that are “inefficient” in the sense that most everyone could expect to gain from other feasible policies. Many other kinds of experts also see existing policies as often clearly inferior to known alternatives

There is a widespread feeling that health is special; the rules that are usually used in other policy areas are not applied in health policy. Health economists, for example, tend to be reluctant to offer economists’ usual prescription of competition and consumer choice, even though they have largely failed to justify this reluctance by showing that health economics involves special features such as public goods, externalities, adverse selection, poor consumer information, or unusually severe consequences. Similarly, while some philosophers argue for bioethical conclusions based on very general ethical intuitions,1 many others rely on moral intuitions that are specific to health and medicine to draw conclusions that are meant to apply mainly in health and medicine. For example, many authors appear to start from the strong moral intuition that it typically seems wrong to deny poor people access to health care, and then seek moral principles that can both account for such intuitions and justify the claim that people have some sort of right to health care.2 In metaethics, opinions on moral intuitions range from an extreme intuitionism, which accepts all case-specific moral intuitions at face value as reliable moral guides, to an extreme foundationalism, which rejects such intuitions as evidence regarding correct general moral principles. Between these extremes, opinions vary on how severe the errors in our moral intuitions are. The practice of bioethics seems to favor the extreme intuitionist end of this spectrum, and thus implicitly expects mild errors.3 In contrast, this essay will suggest that common practice in bioethics has seriously underestimated the errors in our moral intuitions. In this essay, I consider the evolutionary origin of our moral intuitions, but avoid the extreme positions of moral skepticism and “whatever evolved must be good,” both of which are commonly associated with evolution-