From: Damien Broderick (d.broderick@english.unimelb.edu.au)
Date: Fri Mar 08 2002 - 21:56:24 MST
http://www.newscientist.com/news/news.jsp?id=ns99992003
Some people have a special gift for predicting the twists and turns of
chaotic systems like the weather and perhaps even financial markets,
according to an Australian psychologist.
Richard Heath, who has now moved to the UK's University of Sunderland tried
to identify people who can do this by showing volunteers a list of eight
numbers and asking them to predict the next four. The volunteers were told
that the numbers were maximum temperatures for the previous eight days. In
fact the numbers were computer-generated: some sets were part of a chaotic
series while the rest were random.
Random sequences are by their nature unpredictable, whereas chaotic
sequences follow specific rules. Despite this, chaotic sequences are very
hard to predict in practice because of the "butterfly effect" - even an
unmeasurably small change in initial conditions can have a dramatic impact
on their future state.
Nonetheless, Heath found that a quarter of the people he tested could
predict the temperature for at least the next two days if the sequence was
chaotic, rather than random, even though there is no obvious pattern to the
figures.
"The $64,000 question is what is going on in their heads," says Heath. He
is now planning studies to find out whether the skill is related to
specific personality types, or to aspects of intelligence such as
mathematical ability.
David Gilden, a psychologist at the University of Texas in Austin, doubts
that people can detect the next step in any sequence that lacks a
perceptible pattern. "It's a strong claim, to assert that the skill only
exists implicitly," he says.
But others are convinced that Heath is onto something. "It's sound. The
effect looks real," says artificial intelligence expert Jeff Pressing of
the University of Melbourne.
He and others point to a crucial difference between this and previous
studies claiming to show that people can identify the patterns in chaotic
systems: Heath distinguished between the effects of chaos and other
characteristics of the sequences that might help people make correct
predictions.
In particular, Heath was able to exclude the possibility that the people
making successful predictions were doing so by looking only at the last few
numbers. In other words, they were not able to cheat by assuming that "the
weather tomorrow is likely to be the same as the weather today".
If the finding does stand up, testing for sensitivity to chaos might help
financial institutions identify people who would do well as financial
traders. "Some guys can't communicate what they are doing, but they make
millions," says Pressing. "They have some sort of intuition. My guess is
that they are sensitive to subtle non-linear structures like chaos."
Journal reference: <I>Nonlinear Dynamics, Psychology, and Life Sciences</I>
(vol 6, p 37)
Damien Broderick
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