Monthly Archives: January 2007

Follow Your Passion, From A Distance

(Today my graduate research class begins; here is advice for new researchers.)

"Son, don’t marry for money; hang around rich girls and marry for love." A joke I heard years ago from Chip Morningstar

Research topics work similarly.  Don’t research a topic because it is popular; expose yourself to many popular topics and you will fall in love with a few.  Fall in love with a dozen topics; too few and you’ll linger too long after they fail.  Consider:

Fred, Ned, and Ted had never left their home town, but wanted careers as explorers.  They heard others had explored hills and caves nearby, but that seemed boring; they read of famous explorers going more interesting places.  So Fred, Ned, and Ted got out a map and chose their first places to explore: the deepest ocean, the longest cave, and the moon.   They were never heard from again.   

To learn to explore, first follow the paths of previous explorers, first on a map, then from the air, then down on the ground.   Next, try going a mile off of one of those paths.  Then ten miles, then one hundred.   Similarly the best way to start researching is to take a good research paper and really understand it.  Then make a minor change, such as an assumption or data analysis technique.  Then make bigger changes. 

Another problem with passion is bias.  Especially in social science, people pick topics in order to convince the world of their one true answer.  But it is healthier to focus on questions, not answers.  By picking an answer before you’ve really studied a topic, not only are you more likely to be wrong, but more important, you could miss interesting new angles.

My colleague Bryan Caplan is the sharpest thinker I’ve personally known.   He has a penetrating insight and willingness to embrace uncomfortable conclusions, except on a few topics, such as free will, dualism, and libertarian ethics, where he developed strong intuitions early.  Fortunately for Bryan, while these opinions may motivate his research, he had not directly worked in those areas.  Similarly, I have to admit it was good that I spent most of research time away from the topics I was the most passionate about.

GD Star Rating
loading...
Tagged as: , ,

A Model of Extraordinary Claims

Last week I claimed that the saying "extraordinary claims require extraordinary evidence" is appropriate anytime people too easily make more extreme claims than their evidence can justify.  Eliezer, however, whom I respect, thought the saying appropriate anytime people make claims with a very low prior probability.  So I have worked out a concrete math model to explore our dispute.  I suggest that if you are math averse you stop reading this post now. 

Continue reading "A Model of Extraordinary Claims" »

GD Star Rating
loading...
Tagged as: ,

Socially Influenced Beliefs

The discussion of the atheistic tendencies of professors leads me to posit the following.

1.  Suppose that we say that beliefs are primarily influenced by social considerations.  You believe X because you want to earn the friendship/respect of people around you.  So, if you are around God-fearers, your social instinct is to believe in God.  If you are around atheists, your social instinct is to be atheist.

2.  Suppose that you are inclined to believe x.  If your reference group does not believe x, then you will pay attention to evidence against x and reconsider your position.  However, if the group also believes x, you will want to search for evidence in favor of x and to be skeptical about evidence against x.  That is, we try pretty hard to align our thinking to conform to that of our reference group.

3.  Even our belief in mathematical and scientific propositions has a social component to it.   

4.  Academic intellectuals learn something of how to question beliefs in a rational way.  This makes them a bit less inclined to fall for popular superstitions.

5.  However, even academic intellectuals are leery of questioning beliefs within their own reference group.  So it is possible for a group of academics to get stuck in an equilibrium in which they believe a dubious proposition.  One hopes that eventually someone comes along and questions the conventional wisdom in such a way as to disturb that equilibrium.

6.  The atheism of academics looks like an equilibrium.  I think it is a sound one.  However, other equilibrium beliefs among academics strike me as more problematic.  That is, a huge majority of academics may hold some political views, and I do not share those views.

GD Star Rating
loading...
Tagged as:

Agree with Yesterday’s Duplicate

A week ago I tried to offer a clear example of justified disagreement.   Today, I try to offer a clear example where disagreement is not justified.   Imagine:

On Star Trek, a "transporter" moves people by scanning the location of all their atoms, and then constructing a new version in another location, with all the same sort of atoms in the same relative locations.   Yesterday you entered such a transporter, except that this version did not destroy the original copy as did the one on Star Trek.  So a minute after you entered the transporter there were two of you, with identical personality, memories, and cognitive styles. 

You each spent the last day separately reviewing material supplied by supporters on opposite sides of some controversy, such as which side was most responsible for a particular war.  You have just sat down across a table from your duplicate, and you have just told each other that you found your material reasonably persuasive.  This surprised you; how could he think that?  Although you understand abstractly that he is your day-old duplicate, you have a hard time relating to him.  He does not sound or look or act the way you think you do.   Your initial intuition is to treat him like anyone else with views contrary to yours; he must be missing something you see.   How much should you follow this intuition, versus consciously forcing yourself to agree?

This seems to me a clear case where you should try as hard as possible to satisfy the rationality constraint "we can’t forsee to disagree."   While both of you have many biases, and are far from Bayesian, you have almost no good reason for thinking that his biases are worse than yours.   Yes it is possible that he acquired a mental problem in the last day, and his taking on a strange view may be some evidence for that.  But it is at best only very weak evidence; the odds are pretty overwhelming that he is no less rational than you.

As before, it is interesting to think about which variations on this scenario would justify larger disagreements.

Added: I had in mind the case where you and he have not had time to review exactly all the same material; you must react instead to his opinion.       

GD Star Rating
loading...
Tagged as:

Outside the Laboratory

"Outside the laboratory, scientists are no wiser than anyone else."  Sometimes this proverb is spoken by scientists, humbly, sadly, to remind themselves of their own fallibility.  Sometimes this proverb is said for rather less praiseworthy reasons, to devalue unwanted expert advice.  Is the proverb true?  Probably not in an absolute sense.  It seems much too pessimistic to say that scientists are literally no wiser than average, that there is literally zero correlation.

But the proverb does appear true to some degree, and I propose that we should be very disturbed by this fact.  We should not sigh, and shake our heads sadly.  Rather we should sit bolt upright in alarm.  Why?  Well, suppose that an apprentice shepherd is laboriously trained to count sheep, as they pass in and out of a fold.  Thus the shepherd knows when all the sheep have left, and when all the sheep have returned.  Then you give the shepherd a few apples, and say:  "How many apples?"  But the shepherd stares at you blankly, because they weren’t trained to count apples – just sheep.  You would probably suspect that the shepherd didn’t understand counting very well.

Now suppose we discover that a Ph.D. economist buys a lottery ticket every week.  We have to ask ourselves:  Does this person really understand expected utility, on a gut level?  Or have they just been trained to perform certain algebra tricks?

Continue reading "Outside the Laboratory" »

GD Star Rating
loading...

Symmetry Is Not Pretty

From Chatty Apes we learn that symmetry has little to do with whether a face is attractive:

Measurable symmetry accounts for less than 1% of the variance in the attractiveness of women’s faces and less than 3% of the variance of the attractiveness of men’s faces.  … the initial studies showing big effects typically involved samples of less than 20 faces each, which is irresponsibly small for correlational studies with open-ended variables.  Once the bigger samples starting showing up, the effect basically disappeared for women and was shown to be pretty low for men.  But no one believed the later, bigger studies, even most of their own authors — pretty much everyone in my business still thinks that symmetry is a big deal in attractiveness.  So, the first lesson I learned:  Small samples are …  My solution has been to ditch the old p<.05 significance standard.

I see the same thing in health economics; once people see some data supporting a  theory that makes sense to them, they neglect larger contrary data.   

GD Star Rating
loading...
Tagged as: ,

Some Claims Are Just Too Extraordinary

"I would sooner believe that two Yankee professors would lie, than that stones would fall from heaven."

— Thomas Jefferson, on meteors

"How would I explain the event of my left arm being replaced by a blue tentacle?  The answer is that I wouldn’t.  It isn’t going to happen."

— Eliezer Yudkowsky, "A Technical Explanation of Technical Explanation"

"If a ship landed in my yard and LGMs stepped out, I’d push past their literature and try to find the cable that dropped the saucer on my roses. Lack of a cable or any significant burning to the flowers, I’d then grab a hammer and start knocking about in the ship till I was convinced that nothing said “Intel Inside.” Then when I discovered a “Flux Capacitor” type thing I would finally stop and say, “Hey, cool gadget!” Assuming the universal benevolence of the LGMs, I’d yank it out and demand from the nearest "Grey” (they are the tall nice ones), “where the hell did this come from?” Greys don’t talk, they communicate via telepathy, so I’d ignore the voice inside my head. Then stepping outside the saucer and sitting in a lawn chair, I’d throw pebbles at the aliens till I was sure they were solid. Then I’d look down at the “Flux Capacitor” and make sure it hadn’t morphed into my bird feeder. Finally, with proof in my hand and aliens sitting on my deck (they’d be offered beers, though I’ve heard that they absorb energy like a plant) I’d grab my cell phone and tell my doctor that I’m having a serious manic episode with full-blown visual hallucinations."

— Peter K. Bertine, on the Extropian mailing list

Continue reading "Some Claims Are Just Too Extraordinary" »

GD Star Rating
loading...

Women’s Mathematical Abilities

Former Harvard President Larry Summers lost his job for suggesting that researchers consider the possibility that biology partially explains the dearth of female science professors. 

Some psychologists believe that if women are told they are less likely than men to be good at math then women will suffer from a “stereotype threat” that reduces their performance on math tests.

Let’s assume that this stereotype threat is real but also that there is some evidence that men are more likely than women to be born with the exceptionally strong mathematical ability needed to be a science professor.  (Full disclosure:  When I started college I wanted to be a theoretical physicist.  I quickly realized I wasn’t good enough at math to accomplish this dream.)

Many professors, especially at the women’s college where I teach, discuss in class how society might and might not be discriminating against women.  Should these professors discuss possible biological reasons for why men and women don’t achieve equal career outcomes?

GD Star Rating
loading...
Tagged as:

Benefits of Cost-Benefit Analyis

Cass Sunstein in ‘Cognition and Cost-Benefit Analysis‘ thinks at least six cognitive biases can be overcome by pushing your mind through a cost-benefit analysis.

Loss Aversion, Endowment Effects, and Ignoring Trade-offs are obviously all about cost-benefit arithmetic — addition and subtraction, mainly. The Availability Heuristic — the tendency to base  decisions on whatever memories are most vivid or quickly available — is counteracted by cost-benefit analyses’ foregrounding of less vivid and more remote but clearly probative information.

This also addresses Informational and Reputational Cascades based on Availability bias — people would believe the sky is falling if Al Gore told them,  but if he doesn’t mention how much it would cost to prevent, just the hazards of not doing it ….. You really need to look at both the costs and the benefits.

Most generally, explicit cross-comparisons of cost-benefit ratios between alternative courses of action foregrounds the incoherence of our belief systems; coherence is often what we seek to maintain by mobilizing our biases, but often the world doesn’t come furnished with coherence.

While teaching a course on Lomborg’s Copenhagen Consensus (‘ Global Crises, Global Solutions’ Cambridge University Press, 2004 — it’s all cost-benefit analyses) mere exposure to the analyses caused noticable shifts (even in elderly students) in deeply held views on topics including Climate Change, Migration and Free Trade.

GD Star Rating
loading...
Tagged as:

Godless Professors

Last November we learned that the US public believes in God more than college professors, who believe more than professors at elite schools:

Almost a third answered "none" when asked their religion — more than twice the percentage found in the general population.   Science professors were the least religious. Accounting professors were the most religious.   More than half the professors at places other than so-called "elite" universities said they absolutely believed in God. About a third of the professors at elite schools took that position. … About 30 percent of community college professors considered intelligent design as a serious scientific alternative. Fewer than 6 percent of professors at elite universities took that position.

If all we know about a view was that professors held it more, and elite professors even more so, we would be inclined to favor that view.   But other considerations can be relevant; if we knew elite professors favored increasing elite research funding, we might attribute that to self-interest bias.  So should we favor elite professors’ views on God, or can we identify other relevant considerations?   

Added: Tyler Cowen dares us to answer, so let’s list explanations of this correlation:

Continue reading "Godless Professors" »

GD Star Rating
loading...
Tagged as: , ,