The practice of paying for other people’s wisdom is not a new concept. People have been writing philosophical books and documents for thousands of years, and the ways in which we pay for others’ ideas have only grown.We pay for self-help books, workout guides, and cookbooks. We watch premium TV shows featuring great scientific minds and historical scholars. But no one has ever sat down and figured out how much, exactly, thoughts are worth. A recent paper published in the Journal of Interdisciplinary Science Topics takes a very literal look at the phrase “a penny for your thoughts.”

The study, written by Osarenkhoe Uwuigbe, a student at the University of Leicester’s Centre for Interdisciplinary Science, investigated just how much energy is needed to produce thought, and what that energy is valued at.

For simplicity, Uwuigbe used a model that set the power necessary for the brain to run as the power necessary to produce thought. The brain uses about 20 percent of the body’s energy. A typical adult consumes about 100 watts, so it was calculated that the power necessary to run the human brain is about 20 W. Therefore, it takes 20W to produce thought, according to the paper.

To apply monetary value to this energy, the price per kilowatt hour (kWh) charged by energy companies in the UK was calculated, ending up at 16 pence per kWh. Working with the assumption that 20 W or 1/50 nW is the energy required for thought, charging 16p per kWh would mean that one penny could purchase 1/16 of a kWh. This means that the length of time a penny can purchase thought for is three hours, seven minutes, and 30 seconds.

Uwuigbe recognizes the limitations of such a study.

“This model is likely to be an underestimate as power required for the brain to operate does not necessarily translate to power used in thought,” he wrote. “The brain has several autonomic functions it carries out during thought processing and as a result thought processing could not take 100% of the power consumption of the brain.”

Also, the study rests on the assumption that one could speak as quickly as they can think, in order to deliver the monologue of thought.

“It is unlikely that it is possible to think as fast as you speak due to delay caused by biological constrains such as conduction velocity of nerves carrying the signal from the brain to the mouth, the release of Ca2+ ions during muscle contraction of the tongue and lips and so on,” he wrote.

Though it may not be the basis for a new way to charge people for thoughts (we’d all be paying a lot less), the study gives an interesting perspective on the attempt to quantify and value human contemplations.

Source: Uwuigbe O. A Penny For Your Thoughts. Journal of Interdisciplinary Science Topics. 2015.