Perceptions of Randomness
One area of interest of mine is how people understand random events, and use
the concept of randomness in their daily lives. To this end, there are
several programs of study I have been working on.
Retrospective Gambler's Fallacy
Psychologists have known for a long time that people seem to distrust streaks
in random series. In fact, people often behave as though streaks are more
likely to end than chance would dictate. This is called the gambler's
fallacy. A simple illustration of the gambler's fallacy is the fact that
after a coin has landed on heads five consecutive times, people are more
likely than chance to predict that the next flip will land on tails.
It turns out that people demonstrate the gambler's fallacy for events that
have already occurred in addition to making predictions about the
future (imagine I flipped a coin 6 times a half hour ago, the
first 5 landed on heads, what do you think the 6th landed on). Since
people's memories are reconstructive, it seems plausible to imagine that our
memories of past events that we believed to be random will be biased by our
perception of what randomness should look like. Therefore, if past random
events exhibit streaks (as they inevitably will given enough time), we should
have systematic memory errors. The extent of these biases are one topic of
investigation.
Probability Matching
Imagine an unbalanced coin in which heads came up 60% of the time. If you
were to try and predict the outcome of the coin, what percent of the time
should you select heads to lead to optimal performance? The correct answer
is 100%. However, most people probability match: they choose heads 60% of
the time. Why is it that people use this non-optimal strategy?
One possibility is that people are looking for patterns in the data. That
is, people may believe that randomness has a certain "look" that they can
predict. One area of interest is investigating whether people are 1) looking
for a particular "prototypical" set of outcomes and 2) Whether people are
sensitive to deviations from true randomness, so as to be able to effectively
pick up patterns.
Gambler's Fallacy and Hot Hand Bias
As described previously, the gambler's fallacy is a predisposition to
believe that streaks are about to end. However another bias that has been
identified in the literature is the hot hand bias: the belief that a person
is "hot" or "on a roll" and that the streak is likely to continue. Although
both of these biases have been demonstrated -- both in the laboratory and the
real world -- they make diametrically opposed predictions.
It is still unknown exactly when and why people will exhibit each of these
biases. Possible mechanisms include causal theories, motivational biases,
sequential vs. simultaneous display, quality of "win" and many others. One
area of interest is to try to tease apart when people exhibit the gambler's
fallacy, and when they exhibit the hot hand fallacy.
What is randomness
What exactly is random? Most people agree that a coin flip is more random
than whether Michael Jordan will make his next three pointer, but why is this
so? A coin's outcome is predetermined -- if one knew all the forces
that were acting on the coin (e.g. gravity, wind resistance, the flipper's
finger) one could predict the outcome with certainty. What about this leads
one to think it is random?
Although a formal definition of the abstract concept of randomness is best
left to philosophers, psychology has done little to explore people's beliefs
of what is random, and what elements predict those beliefs. To this end, one
area of inquiry is to establish what factors are involved in people's a
priori expectations of a random process.
I have many more research interests as well. go back
to the homepage to look at them further.