Who Believes in Science?

Or Religion

Race and Gender

A common charge against Christian fundamentalists is that they do not believe in evolution. It is true of many of them — but of many of their critics as well, if one judges belief in a theory by willingness to accept its implications even when you don’t want to.

One implication of evolution is that organisms, including humans, are "as if" designed for reproductive success. The central difference between males and females is their role in reproduction. It is not logically impossible for the same design to be optimal for both roles but it seems unlikely and there are multiple differences between men and women in easily observed physical characteristic, including some, such as height and running speed, not directly linked to reproduction..

The same logic implies that, while it is not logically impossible that the same intellectual and behavioral characteristics are optimal for male and female, it is not what one would expect. Hence one implication of evolution is that outcome differences could be partly or entirely the result of differences in the distribution of intellectual and behavioral, as well as physical, characteristics of the sexes.

One such difference is the shortage of female math and physics professors at elite schools. That might be explained by discrimination against women but might also be explained by the tighter distribution of female intelligence — fewer morons, fewer geniuses. That might in turn be explained by the higher variance in reproductive success of males, due to the fact that the scarce reproductive input, wombs, is possessed by women. A very successful man can father more children than even a very successful woman can bear, even an unsuccessful woman is likely to have children, an unsuccessful man not. Since being male is, reproductively speaking, a high risk profession, it might make sense for evolution to design males as humans design sports cars, for high performance when everything works at the cost of low performance if it doesn’t.

That is a guess and might be wrong, but it illustrates a possible explanation of outcome differences for someone who takes seriously the logic of Darwinian evolution. Yet discussions of outcome differences for men and women routinely treat differences as evidence of discrimination, implicitly assuming away the possibility of innate differences.

Humans differ from other primates in, among other things, their intelligence. Darwinian evolution can only work for characteristics that are heritable. Hence it follows that if humans were produced by evolution, intelligence must be heritable.¹ Human races as conventionally defined are descended from populations that evolved in different environments, faced different selective pressure. Hence while it is possible that people whose ancestry is mostly from Europe, people whose ancestry is mostly from sub-Saharan Africa, and people whose ancestry is mostly from East Asia, all have the same distribution of intellectual and behavioral characteristics, there is no reason to assume they do. They are, after all, observed to have different distributions of easily observed physical characteristics — that is how we know whose ancestry is from where hence how we classify people by race.

It follows that there is no good a priori reason to expect the distribution of characteristics to be the same for different races as conventionally defined, hence no reason to attribute all differences in outcomes by race to discrimination. Some or all such differences might be due to innate differences in the distribution of characteristics, including intelligence.

Many people, most of whom claim to support science and believe in evolution, argue on the implicit assumption of no relevant innate differences between the distribution of characteristics of different races or different genders. Hence they do not believe in evolution, at least if they are intelligent enough to follow the logic of arguments such as the one I have just offered.

Climate Change

Another area where some people accuse others of not believing in science is climate change. The charge is quite often true — both of those it is made against and of those who make it.

A large fraction of talk about climate change treats it as an imminent catastrophe, capable of destroying civilization, perhaps humanity, in the near future.² Contrast that to the view of William Nordhaus, who received a Nobel prize for his work estimating its net effects. By his calculation, if nothing is done about climate change the result by the end of this century will be a reduction in human welfare relative to what it would be without climate change equivalent to a reduction of annual world output by 2.5%.³ He argues for action to reduce climate change but offers realistically modest estimates of the cost of not doing so.

It is not just Nordhaus. The Summary for Policy Makers sections of the successive IPPC reports emphasize the desirability of action against climate change but if you read the body of the reports you discover that the projected effects are very far from catastrophic.

My own view, which I have defended here⁴ and elsewhere, is that both Nordhaus and the IPCC are unduly pessimistic, that climate change will have positive and negative effects, both spread out over a long and uncertain future and of uncertain size, that it is not even clear whether the net effect will be negative although it might be. That is very much a minority view. The consensus among scientists working in the field is that climate change is a problem, if not dealt with will have substantial negative effects, but effects far short of destroying human civilization or the human race.

Those who claim the contrary could conceivably be right — climate is a complicated system and the future uncertain — but their position is not supported by current climate science.

For responding to the view that the Earth will be unable to support life if it gets substantially warmer, I like to point to global temperature in the geological past. The blue portion of the graph represents ice ages, times when there was ice on one or both poles.

Radiation Risks

Another area where people who claim to believe in science frequently do not is the danger of radiation, especially from nuclear reactors. Randal Munro of XKCD offers an informative chart of the radiation exposure from a wide variety of sources, ranging from sleeping next to someone (0.05 microsieverts) to a dose that is fatal even with treatment (8 sieverts). In between are the average total dose from the Three Mile Island accident to someone living within 10 miles (80 microsieverts), the yearly dose from the natural potassium in the body (390 microsieverts) and the dose received by two Fukushima plant workers (~180 millisieverts).

Accepting those figures would reduce the usefulness of fears of radiation to anti-nuclear activists, at least ones unwilling to come out against CRT monitors, bananas and cohabitation.

Almost everyone believes in science when it supports what he wants people to believe, almost nobody when it doesn’t.

Not Just Science

The pattern of people believing in something until it’s implications become inconvenient is not limited to science. It applies to religion too.

Under biblical law, all debts were to be cancelled every seventh year. This raised a problem for someone who wanted to borrow money in the sixth year from a lender who could not expect ever to get it back. The problem was recognized in the original text, which urged lenders to lend to their fellows even in the sixth year. It was eventually dealt with by Hillel, who constructed a legal form, Prosbul, which permitted the creation of a debt immune from cancellation in the seventh year. (Legal Systems Very Different from Ours, Chapter 4)

Jewish law forbade Jews from lending at interest to each other. Christian and Muslim law, as commonly interpreted, forbade believers from lending at interest to anyone.⁵ In all three systems legal devices were invented to permit evasion of that restriction; one example was to contract for a loan in one currency to be repaid in in another, with the latter amount larger than the former at the then prevailing exchange rate. Since the exchange rates might change between lending and repaying, it was not certain that the terms implied a positive interest rate.

A modern approach to the problem is an “Islamic Mortgage.” The bank buys the property the borrower wants to buy and rents it to the borrower, with part of his payment going to pay off the loan. The bank gets back more than the price of the house, hence is actually collecting interest, but in the form of rent, hence viewed as consistent with the ban on interest. Three different versions exist, all with the same underlying logic.

Links

From time to time I come across something online that strikes me as interesting. Inspired by Scott Alexander but less ambitious — I have not yet discovered his formula for the forty-eight hour day — I will provide links but only brief commentary.

Ice cream may be good for you but it doesn’t do to say so, even if it is what your own research shows. I was pointed at this by a commenter on my previous post, have now added it.

Someone on FB linked to a Usenet thread I was part of more than twenty years ago. It started with an orthodox (ARI) Objectivist proposing a solution to the problem of Iranian terrorism:

"Teheran has some ten million people or so. About eight hours from my time now it will be noon on Thursday in Teheran. At that time I say we issue an ultimatum. We tell Iran that they have forty-eight hours to give up their terrorists -- all of them -- and completely cease all terrorist activities. If they do not comply by noon on Saturday, we will destroy Teheran with a nuclear bomb."

That set off a long argument, with some people supporting the proposal, some, myself included, opposing it. For a sample of the former:

Here is the rule: if you live in a terrorist state, you are going to be a target of the country you target.

The first and second “you” refer to an individual Iranian, the third to his government.

The instinct for thinking in terms of collectives was powerful enough to persuade even people committed to an individualist ideology to hold individual Iranians responsible for the misdeeds of the government that rules them.

On the subject of libertarian beliefs and their basis — I consider Rand a libertarian, although she did not agree — I had an interesting debate at Porcfest with Gene Epstein on the question of whether “The right way to persuade people of libertarianism is by showing them that its outcomes are superior without any resort to the flawed non-aggression principle.” I took the positive.

After the debate it occurred to me that one additional point I should have made was that many arguments using the NAP hinge on the claim to own things, in particular land. But most land ownership claims are dubious in terms of libertarian theory, since much, perhaps most, land ownership is due to conquest, at least if you trace the chain of title far enough back. That not only undercuts claims of land ownership but claims to own things whose claimed ownership is derived from claims of land ownership, such as a loaf of bread.

1. There is empirical evidence that intelligence is in large part heritable, due in part to identical twin studies such as those done by Cyril Burt, mentioned in a previous post. But my point is that even without such evidence there is good reason to believe it is, at least for those who believe in evolution.

2. For an extreme example:

“Millennials, and Gen z, and all these folks that come after us, are looking up and we’re like ‘the world will end in 12 years if we don’t address climate change, and your biggest issue is how are we gonna pay for it?'” @AOC #MLKNow #MLK2019 pic.twitter.com/fbUxr2C0tJ

3

“the best guess in this book is that the economic damages from climate change with no interventions will be on the order of 2.5 percent of world output per year by the end of the twenty-first century” (A Question of Balance, p. 6)

4. A summary of my argument. Two criticisms of writing in the field. One large positive effect usually ignored. All from posts here.

5. In the case of Muslim law some scholars argue that riba, which is forbidden, meant “the doubling of a sum owed (capital and interest, in money or in kind) when the debtor cannot pay it back at the moment when it falls due” (Maxime Rodinson, Islam and Capitalism), but the ban on riba” is usually interpreted as applying to any interest.