Old ideas die hard, including the belief the eyes send out invisible beams that can affect what we are looking at. People might agree that talk of someone's piercing gaze is just metaphorical, but it seems underneath it all we just may believe our eyes have the power to apply forces to the things.
When Professor Michael Graziano of Princeton University asked 724 participants in a study if they believed people could exert forces with their eyes, only 5 percent said yes. After all, philosophers have reasoned for 2,500 years that eyes must work through light entering them, not leaving. However, Graziano reports in Proceedings of the National Academy of Sciences that when he tested a subgroup's subconscious attitudes, the results were quite different.
Graziano showed 157 subjects images of paper tubes of different heights and diameters and asked them to guess how far they could be tilted without falling over. The images included a photograph of a man referred to as Kevin staring at the tube, but sometimes he was blindfolded.
When Kevin's eyes were open, participants thought the tube could be tilted more strongly towards him than away. For images where he was blindfolded, or when told the tube was made of heavy material, this difference disappeared. The responses would have been correct if Kevin was producing invisible beams from his eyes that the tube could rest against when tilted towards him, but would help push it over when the tilting went the other way.
The differences in responses were small – just 0.64º on average, but highly statistically significant. Graziano and co-authors calculated the estimates would be right if Kevin's eyes exerted a force of less than one-hundredth of a Newton, “similar in magnitude to a barely detectable breeze.” Even when they discounted the seven subjects who openly believed that the eyes exert a force, it still didn't change the results.
The authors note that there is an extraordinary persistence across cultures of “the belief the eyes emit an invisible energy,” something assumed by almost all children. Scientific demonstrations that this isn't true seem to be fighting against deeply embedded presumptions. The findings are evidence for Graziano's theory that people “construct a rich, implicit model of other people’s active visual attention.”
The study is part of Graziano's specialization in the study of peripersonal space, or the “personal bubble”, that defines how we relate to inanimate objects and interact with people.
Graziano is known for his original approaches, including performing ventriloquism in lectures using an orangutan puppet, also named Kevin. He uses the way our brains attribute consciousness to puppets as an example of the way humans as social creatures project models of other's thoughts. We're sure we'd have paid much more attention to our university classes if they were anything like that.