There is a direct correlation between the size of a person’s pupils and their decision in the majority of decision making scenarios involving a yes or no type decision according to new research conducted by psychologists from the Netherlands and neuroscientists from Germany that was published in the Jan. 20, 2014, edition of the journal Proceedings of the National Academy of Sciences.
The researchers found that test participant’s pupils dilated to a greater extent in preparation to a yes response to yes or no decision and dilated less when deciding no to the same decision. The researchers also found that deciding yes against a personal bias also produced a greater degree of pupil dilation.
Pupil dilation reflects the content of the decision maker’s mental process prior to making the final decision and during the decision making process even if the decision goes against a personal bias that the individual may have.
The researchers conclude that pupil size during decision making is a direct measure of a person’s mental state and the person’s brain function during the decision making process.
Potential uses of the research could include terrorist detection in airports, improvement of sales techniques and sales success by observation of pupil size, and potentially gauging the reliability of statements made by politicians, pundits, and newsreaders.