few make order out of chaos
19:00 06 March 2002 Exclusive from New Scientist
Print Edition, Rachel Nowak, Melbourne
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.
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
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
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.
$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
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.
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.
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".
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."
reference: Nonlinear Dynamics, Psychology, and
Life Sciences (vol 6, p 37)
doc found at http://www.newscientist.com/article.ns?id=dn2003