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Quantum Theory May Explain Wishful Thinking
05-20-2009, 02:08 AM, (This post was last modified: 05-20-2009, 02:09 AM by ---.)
Quantum Theory May Explain Wishful Thinking

Quantum Theory May Explain Wishful Thinking

Written by Lisa Zyga
Saturday, 18 April 2009 08:20

Humans don’t always make the most rational decisions. As studies have
shown, even when logic and reasoning point in one direction, sometimes
we chose the opposite route, motivated by personal bias or simply
"wishful thinking." This paradoxical human behavior has resisted
explanation by classical decision theory for over a decade. But now,
scientists have shown that a quantum probability model can provide a
simple explanation for human decision-making - and may eventually help
explain the success of human cognition overall.

If you were asked to gamble in a game in which you had a 50/50 chance
to win $200 or lose $100, would you play? In one study, participants
were told that they had just played this game, and then were asked to
choose whether to try the same gamble again. One-third of the
participants were told that they had won the first game, one-third
were told they had lost the first game, and the remaining one-third
did not know the outcome of their first game. Most of the participants
in the first two scenarios chose to play again (69% and 59%,
respectively) , while most of the participants in the third scenario
chose not to (only 36% played again). These results violate the “sure
thing principle,” which says that if you prefer choice A in two
complementary known states (e.g., known winning and known losing),
then you should also prefer choice A when the state is unknown. So why
do people choose differently when confronted with an unknown state?

In a recent study, psychologists Emmanuel M. Pothos of Swansea
University in the UK and Jerome R. Busemeyer of Indiana University in
the US have presented an alternative framework for modeling
decision-making of this kind, based on quantum probability. As they
note, the original motivation for developing quantum mechanics in
physics was to explain findings that seemed paradoxical from a
classical point of view. Possibly, quantum theory can better explain
paradoxical findings in psychology, as well. In recent years, a
growing number of researchers have investigated using quantum
formalism in cognitive situations, such as in modeling human judgment
and perception. Pothos and Busemeyer’s results are published in a
recent issue of Proceedings of the Royal Society B.

“A few decades ago, Tversky and Kahneman (1974) challenged ubiquitous
assumptions regarding what is the most suitable framework for modeling
human cognition,” Busemeyer told “Until then, most
psychologists sought to understand cognition using classic probability
theory. In our paper we raise the question, which mathematical
framework is most appropriate for cognitive modeling? In this article,
for the first time, we present a fundamentally different, and more
powerful, approach to probabilistic models of cognition, based on
quantum principles. Employing minimal assumptions, we derive a
Hamiltonian directly from the parameters of the problem (e.g., the
payoffs associated with different actions) and known general
principles of cognition (e.g., a well known phenomenon of cognitive
dissonance); every step in our model is psychologically interpreted
and rigorously justified.”

Defecting Dilemma

In their study, the scientists compared two models, one based on
Markovian classical probability theory and the other based on quantum
probability theory. They modeled a game based on the Prisoner’s
Dilemma, which is similar to the gambling game. Here, participants
were asked if they wanted to cooperate with or defect from an
imaginary partner. Overall, each partner would receive larger pay-outs
if they defected, making defecting the rational choice. However, if
both partners cooperated, they would each receive a higher pay-out
than if both defected. Similar to the results from the gambling games,
studies have shown that participants who were told that their partner
had defected or cooperated on the first round usually chose to defect
on the second round (84% and 66%, respectively) . But participants who
did not know their partner’s previous decision were more likely to
cooperate than the others (only 55% defected). It seems as if these
individuals were trying to give their partners the benefit of the
doubt, at the expense of making the rational choice.

As the scientists showed, both classical and quantum probability
models accurately predict an individual’s decisions when the
opponent’s choice is known. However, when the opponent’s action is
unknown, both models predict that the probability of defection is the
average of the two known cases, which fails to explain empirical human
behavior. The problem is that the models are purely rational, meaning
they try to maximize utility.

To address this problem, the scientists added another component to
both models, which they call cognitive dissonance, and can also be
thought of as wishful thinking. The idea is that people tend to
believe that their opponent will make the same choice that they do; if
an individual chooses to cooperate, they tend to think that their
opponent will cooperate, as well. If both partners cooperate, both
will receive a higher pay-out than if both defected. (And if an
individual thought that his opponent would cooperate and so decided to
defect to maximize his own pay-out, he would then be compelled to
assume that the opponent would also defect, according to cognitive
dissonance.) In other words, an individual views his opponent as a
mirror of himself.

The difference between the classical and quantum models lies in how
the rational component and the cognitive dissonance component are
combined. Even after adding the second component, the classical model
predicts that the probability in the unknown scenario must equal the
average of the probability for the two known cases. As such, the
classical model continues to obey the law of total probability, and
fails to explain the violations of the sure thing principle.

In the quantum model, on the other hand, the addition of the cognitive
dissonance component produces interference effects that cause the
unknown probability to deviate from the average of the known
probabilities. While in the classical model an individual is committed
to exactly one preference at any given time, in the quantum model an
individual experiences a superposition of these preferences.
Mathematically, the probability (or amplitude) of defecting in the
unknown scenario is obtained from the superposition of probabilities
(amplitudes) for the two known cases. These interference effects
enable the probability of unknown events to be lower than the
probability of either event individually, which is observed in the
empirical studies.

“Cognitive dissonance can arise in other decision making situations
and is not limited to games with an intelligent opponent,” Busemeyer
said. “In the gambling game, you play against nature. In this case,
however, your belief that you will win the game becomes coordinated
with your intentions to play the game. Cognitive dissonance effects
are not even limited to adult humans but have also been found with
young children and even with nonhuman primates.” (See Egan, L. C.,
Santos, L. R. & Bloom, P. (2007). The origins of cognitive dissonance:
evidence from children and monkeys. Psychological Science, 18, 978-

Quantum Cognition
While classical probability theory is too restrictive to fully
describe human decision-making, this study shows that quantum theory
provides a promising framework for modeling human cognition. In
addition to making accurate predictions of the gambling game and
Prisoner’s Dilemma, the quantum model also agrees with the empirical
evidence that people make the same decision in back-to-back identical
scenarios. In classical models, on the other hand, back-to-back
choices remain probabilistic, which fails to explain human behavior.

“Classic probability theory, including Markov processes, must obey the
law of total probability,” said Busemeyer. “However, human judgments
often exhibit interference effects which violate the law of total
probability. Quantum probability was originally developed specifically
for the purpose of explaining interference effects found in physics.
This same mathematical formalism provides an explanation for
interference of thoughts in human judgments.”

Pothos and Busemeyer hope that further research on quantum probability
models of human cognition could help answer fundamental questions
about the nature of how we think. For example, what does it mean to be
rational? Another example is Schrodinger’s equation, which predicts a
periodic oscillation between choices after a minimum length of time.
This oscillation matches with electroencephalogra phy signals and may
explain why the longer you debate on a decision, the more you
fluctuate. Overall, if our brains use quantum principles, and quantum
computation is known to be fundamentally faster than classical
computation in computers, then perhaps quantum principles can even
help explain the success of human cognition.

More information: Pothos, Emmanuel M. and Busemeyer, Jerome R. “A
quantum probability explanation for violations of ‘rational’ decision
theory.” Proc. R. Soc. B. doi:10.1098/ rspb.2009. 0121.

Last Updated on Saturday, 18 April 2009 08:25
05-20-2009, 03:13 AM,
Quantum Theory May Explain Wishful Thinking
Quantum physicians need to get a life lol
[Image: Palestinian_Dawn_by_Palestinian_Pride.jpg]
05-20-2009, 03:25 AM,
Quantum Theory May Explain Wishful Thinking
smells like another justification for collecting even more data and categorizing human experience.
you gotta see a lot to be a know it all.
05-20-2009, 09:22 AM, (This post was last modified: 06-04-2009, 09:31 AM by rsol.)
Quantum Theory May Explain Wishful Thinking
lolz. couldnt they just assume ppl can be a bit thick?

Personally i sometimes think the wishful thinking can explain many quantum theories:)

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