Quantum Minds: Why We Think Like Quarks

"Yet one big question remains: why should quantum logic fit human behaviour? Peter Bruza at Queensland University of Technology in Brisbane, Australia, suggests the reason is to do with our finite brain being overwhelmed by the complexity of the environment yet having to take action long before it can calculate its way to the certainty demanded by classical logic."

In this article from the New Scientist website, Mark Buchanan discusses human behaviour and whether it is better described as governed by classical logic or quantum logic. He discusses how the mathematics of quantum logic, often applied to particle behaviour, "actually stands on its own, quite independent of the theory....'People often follow a different way of thinking than the one dictated by classical logic,' says [Physicist Diederik Aerts of the Free University of Brussels, Belgium,]. 'The mathematics of quantum theory turns out to describe this quite well.'"

Buchanan describes experiments that show the propensity of humans to violate classical logic in their behaviours and shift to decisions more easily explained by quantum logic.

Giving people the task of categorising demonstrates that people aren't logical, at least by classical standards. But quantum theory "offers richer logical possibilities." There are experiments that "document what psychologists call the disjunction effect - that people often place things in the first category, but not in the broader one -... two possibilities listed simultaneously lead to strange results." However, quantum logic offers the possibility to include an "interference term" that makes quantum logic more flexible and, thus more applicable to human behaviour. "Quantum probabilities have the potential to provide a better framework for modelling human decision making...."

From the information and communication technology (ICT) sector research, quantum logic can be applied to how searches are constructed to include or exclude information. "It seems to work because it corresponds more closely to the vague reasoning people often use when searching for information....We often rely on hunches, and traditionally, computers are very bad at hunches. This is just where the quantum-inspired models give fresh insights."

Buchanan presents the thinking of scientists who believe that quantum logic plays a larger role than classical logic. "Yet one big question remains: why should quantum logic fit human behaviour? Peter Bruza at Queensland University of Technology in Brisbane, Australia, suggests the reason is to do with our finite brain being overwhelmed by the complexity of the environment yet having to take action long before it can calculate its way to the certainty demanded by classical logic. Quantum logic may be more suitable to making decisions that work well enough, even if they're not logically faultless. 'The constraints we face are often the natural enemy of getting completely accurate and justified answers,' says Bruza."

This idea fits with the views of some psychologists, who argue that strict classical logic only plays a small part in the human mind. Cognitive psychologist Peter Gardenfors of Lund University in Sweden, for example, argues that much of our thinking operates on a largely unconscious level, where thought follows a less restrictive logic and forms loose associations between concepts." Buchanan concludes that: "Perhaps only humans, with our seemingly illogical minds, are uniquely capable of discovering and understanding quantum theory."