bias

All posts tagged bias

This book is a colorful explanation of why we are less successful at finding happiness than we expect. It shows many similarities between mistakes we make in foreseeing how happy we will be and mistakes we make in perceiving the present or remembering the past. That makes it easy to see that those errors are natural results of shortcuts our minds take to minimize the amount of data that our imagination needs to process (e.g. filling in our imagination with guesses as our mind does with the blind spot in our eye).
One of the most important types of biases is what he calls presentism (a term he borrows from historians and extends to deal with forecasting). When we imagine the past or future, our minds often employ mental mechanisms that were originally adapted to perceive the present, and we retain biases to give more weight to immediate perceptions than to what we imagine. That leads to mistakes such as letting our opinions of how much food we should buy be overly influenced by how hungry we are now, or Wilbur Wright’s claim in 1901 that “Man will not fly for 50 years.”
This is more than just a book about happiness. It gives me a broad understanding of human biases that I hope to apply to other areas (e.g. it has given me some clues about how I might improve my approach to stock market speculation).
But it’s more likely that the book’s style will make you happy than that the knowledge in it will cause you to use the best evidence available (i.e. observations of what makes others happy) when choosing actions to make yourself happy. Instead, you will probably continue to overestimate your ability to predict what will make you happy and overestimate the uniqueness that you think makes the experience of others irrelevant to your own pursuit of happiness.
I highly recommend the book.
Some drawbacks:
His analysis of memetic pressures that cause false beliefs about happiness to propagate is unconvincing. He seems to want a very simple theory, but I doubt the result is powerful enough to explain the extent of the myths. A full explanation would probably require the same kind of detailed analysis of biases that the rest of the book contains.
He leaves the impression that he thinks he’s explained most of the problems with achieving happiness, when he probably hasn’t done that (it’s unlikely any single book could).
He presents lots of experimental results, but he doesn’t present the kind of evidence needed to prove that presentism is a consistent problem across a wide range of domains.
He fails to indicate how well he follows his own advice. For instance, does he have any evidence that writing a book like this makes the author happy?

Book Review: When Genius Failed : The Rise and Fall of Long-Term Capital Management by Roger Lowenstein
This is a very readable and mostly convincing account of the rise and fall of Long-Term Capital Management. It makes it clear to me how the fairly common problem of success breeding overconfidence led LTCM to make unreasonable gambles, and why other financial institutions that risked their money by dealing with LTCM failed to require it to exercise a normal degree of caution.
The book occasionally engages in some minor exaggerations that suggest the author is a journalist rather than an expert in finance, but mostly the book appears a good deal more accurate and informed than I expect from a reporter. It is written so that both experts and laymen will enjoy it.
One passage stands out as unusually remarkable. “The traders hadn’t seen a move like that – ever. True, it had happened in 1987 and again in 1992. But Long-Term’s models didn’t go back that far.” This is really peculiar mistake. The people involved appeared to have enough experience to realize the need to backtest their models better than that. I’m disappointed that the book fails to analyze how this misjudgment was possible.
Also, the author spends a bit too much analysis on LTCM’s overconfidence in their models, when his reporting suggests that a good deal of the problem was due to trading that wasn’t supported by any model.

Judicial Bias

Finally someone has produced a quantitative measure that tests the ideological biases of supreme court justices, and it shows a good deal of bias. It looks more like a collection of small biases rather than a simple polarization into left and right.
An article titled Alito isn’t “pro-life” or “pro-choice” but “pro-law.” by Jon Adler (who I knew when he was an undergrad and whose opinions I respect) has led me to believe that Alito will be less influenced by his personal biases than the average justice.

Why did many people decide not to leave New Orleans in advance of Katrina? Part of the problem may have been that they relied on storytellers rather than weather experts.
NBC’s Brian Williams reports on his blog NBC’s reaction to this weather alert:

URGENT – WEATHER MESSAGE
NATIONAL WEATHER SERVICE NEW ORLEANS LA
1011 AM CDT SUN AUG 28 2005
…DEVASTATING DAMAGE EXPECTED…
HURRICANE KATRINA…A MOST POWERFUL HURRICANE WITH UNPRECEDENTED
STRENGTH…RIVALING THE INTENSITY OF HURRICANE CAMILLE OF 1969.
MOST OF THE AREA WILL BE UNINHABITABLE FOR WEEKS…PERHAPS LONGER.
AT LEAST HALF OF WELL CONSTRUCTED HOMES WILL HAVE ROOF AND WALL
FAILURE. ALL GABLED ROOFS WILL FAIL…ALL WOOD FRAMED LOW RISING
APARTMENT BUILDINGS WILL BE DESTROYED. … WATER SHORTAGES WILL MAKE
HUMAN SUFFERING INCREDIBLE BY MODERN STANDARDS.

Williams says “The wording and contents were so incendiary that our folks were concerned that it wasn’t real”, and implies that he and others at NBC translated this into something less scary for their viewers.
My most memorable experience with hurricane forecasts was with hurricane Gloria in 1985 when I was in Block Island (off Rhode Island). I recall a TV weather forecast that winds might reach 135 to 175 mph, and marine weather radio forecasts of 50 to 70 knot sustained winds with gusts to 90 knots (i.e. less than 105 mph). The marine radio forecasts seem to be more direct relays of what the weather service puts out, and it was fairly simple for me to determine that the TV forecast was bogus (the marine radio forecasts proved pretty accurate).
So it’s easy to imagine that people are aware that TV forecasts have a habit of overstating the threat from storms, and thought they could infer expert forecasts from TV forecasts by assuming a simple pattern of exaggeration, when it may be that the storytellers have a more complex model of how viewers’ behavior should be manipulated by biasing their reports. Do people actually rely on TV reports rather than more direct and reliable sources of expert opinion when accurate forecasts are important? If so, is it because they use weather forecasts mainly as entertainment or a catalyst for smalltalk at parties, and don’t want to be aware of the flaws?
And of course there was the problem of key government leaders failing to believe the expert forecast: (from The Agitator) [then] FEMA Director Brown:

Saturday and Sunday, we thought it was a typical hurricane
situation — not to say it wasn’t going to be bad, but that the
water would drain away fairly quickly. Then the levees broke and
(we had) this lawlessness. That almost stopped our
efforts…Katrina was much larger than we expected.

Book Review: The Blank Slate : The Denial of Human Nature and Modern Intellectual Life by Steven Pinker
Pinker makes a good case that there’s a widespread bias toward a blank-slate world-view. But when dealing with serious scientific literature, his attempts to find clearcut enemies seem mistaken.
Pinker’s claim that “The second scientific defense of the Blank Slate comes from connectionism” is pretty puzzling. This “defense” consists of modeling the mind as “a general-purpose learning device”. But the books that Pinker references (Rethinking Innateness, and Parallel Distributed Processing), are both careful to point out why their models are completely consistent with the kind of genetic influences on behavior that evolutionary psychologists are talking about. Their disagreements with Pinker seem to be at most about how those influences are implemented, and even there I can’t find anything in Pinker’s arguments that clearly rejects what the connectionists believe.
Pinker’s attacks on Gould’s quasi-defense of the blank slate mainly convinced me that Gould didn’t want to think clearly about the subject, probably because he considered that any mechanistic explanation of the mind (genetic or environmental) was demeaning.
Pinker’s arguments that it’s silly to believe in the tabula rasa and noble savage world-views are eloquent and compelling, but his response to the “it’s demeaning” attitudes will convince fewer people, because he ignores the very real benefits of holding an unrealistically high opinion of one’s self (overestimating one’s abilities seems to be an effective means of advertising one’s strengths). To those who want to portray themselves as angelic or as wiser than software of the future, an accurate model of the mind is genuinely demeaning.
Pinker seems somewhat inconsistent about how important it is to know whether the mind is a blank slate.
On pages x – xi he says “the conviction that humanity could be reshaped by massive social engineering projects led to some of the greatest atrocities in history.” But in the chapter on fear of inequality, he claims (more convincingly), while defending his views from the charge they will encourage Nazism, that the differences between Nazi beliefs in genetic superiority and the blank slate viewpoints of Stalin and the Khmer Rouge didn’t have much effect on whether those tyrannies engaged in genocide – it was the greater tendency to divide people into in-groups and out-groups that best distinguishes the worst of the genocidal tyrants.
Pinker exaggerates the importance of finding the correct answer to the nature-nurture debate in other ways as well (I suppose we shouldn’t be surprised that an author overestimates the importance of what he’s selling).
He gives examples such as forcing people to live in drab cement boxes (as if their taste for a more natural surrounding could be reversed by social engineers), or releasing psychopaths (because societal problems caused their insanity).
But a genetic component to these behaviors doesn’t prove that they can’t be altered (I have genes for brown hair – does that mean I can’t dye my hair blue?). It only gives hints as to why they might be difficult to alter.
It sure looks like careful scientific studies of whether we knew how to alter these behaviors would be a more reliable way of debunking the faulty conclusions.

Alarmism

Last week’s issue of Nature has a review of a recent Michael Crichton book (dismissed as “Viagra for climate sceptics”) which contains an interesting claim about the reaction to the movie The Day After Tomorrow:

Surveys of public opinion conducted before and after the film was released found that it made people think climate change is less likely

Apparently its obvious lack of realism caused people to associate the more respectable claims about global warming with Hollywood escapism.
I wonder if this is the tip of a much larger iceberg. It seems to me that a wide variety of political movements tend to promote the most alarmist versions of their ideas in order to get respect and/or money from their strongest supporters. I don’t find it hard to imagine that it is common for activist groups to hurt the causes they claim to be fighting for by sounding unrealistic to swing voters.