Why do humans seem to have such a keen awareness of other peopleâ€™s gaze?
Primates in general are uniqueÂ amongÂ animals in the degree with which we can actually move our eyeballs within our eye sockets.Â This allows us to quickly shift our visual attention, without actually moving our head.Â Other mammals aside from primates also have keen abilities to sense when others are observing them.Â Humans in particular however, have a unique ability to accurately gauge where someone is looking, even when the individual isnâ€™t looking at them.
The evolutionary advantages conferred by this unique ability are obvious: being able to quickly determine where another animalâ€™s attention is being focused allows humans to quickly prepare for fight or flight.Â And as fleshy primates with very little in terms of physical ability, claws or big nasty teeth, being able to quickly detect danger was essential to early manâ€™s survival.Â But the advantages of this ability extend well beyond surviving attacks from predators.
As social creatures, itâ€™s also important for humans to be able to read other members of our own species.
If youâ€™re under scrutiny from a more physically or socially dominant member of your society, then you had better act accordingly.Â For intelligent, social creatures like humans, being able to determine where another human being is looking helps to decipher what theyâ€™re thinking about.Â This can even have benefits beyond survival.Â For example, the ability to link a gaze to a particular person or object is essential to language learning.Â Eye contact can also be a sign of intimacy rather than hostility, depending on other environmental/social cues.Â Thereâ€™s a reason that someone wearing cheap contact lenses that blackout or whiteout the iris looks â€œsoullessâ€ â€“Â Â discount contact lenses that block a personâ€™s pupils takes away their ability to make intimate eye contact, and also reduces our ability to determine what theyâ€™re thinking.
How Do We Detect A Gaze?
When youâ€™re observing another personâ€™s gaze, there are a number of subconscious processes that rapidly get triggered.Â Your brain will analyze the pupil and iris of the eye in relation to the whites of the eye.Â This indicates where the eye is pointed.Â When the pupil is exactly in between the two whites of the eyes, we sense that the person is looking straight at us.Â Head direction also provides a cue that allows us to quickly determine where someone is looking.Â The brain will do some subconscious geometry based on the head and relative eye angle, in order to determine the direction of a gaze.
Can We â€œSenseâ€ a Gaze Behind Our Head?
Weâ€™ve all experienced it before â€“ we sense a gaze or a stare from behind, and turn around to face it only to have our suspicions confirmed. Â But if our brain normally detects and processes a gaze by analyzing the ratio of dark to light in the eye and head direction, how does the brain detect someone looking at us from behind?Â Can we in fact detect a gaze from behind, through some sort of mysterious 6th â€œsenseâ€?
One potential explanation for this phenomenon has to do with theory of mind â€“ our ability to infer what someone is thinking based on our knowledge of human behavior/psychology and environmental factors.Â If we expect someone to be looking at us in that moment, we may â€œfeelâ€ a gaze even if we have no way to visually confirm it.Â Perhaps weâ€™re wearing something that makes us stand out and feel self-conscious, perhaps we walked by a person earlier who quickly checked us out and we expect them to take another look once theyâ€™ve passed us by.Â Far from being magic or a â€œ6th senseâ€, there are lots of subtle cues processed quickly and imperceptibly by our subconscious brain that allow us to make accurate judgments about a wide variety of phenomena that our conscious brain has little opportunity to process.
Most of the time however, the perceived ability to â€œsenseâ€ if someone is looking at us from behind, is simply a result of our own confirmation bias.Â When someone is behind you and you believe theyâ€™re looking at you, and you turn around to confirm your belief, anytime youâ€™re correct youâ€™ll mentally record it as proof of your suspicions.Â What you neglect to remember however, is all the times you turn around, only to find no one looking.Â This is the same type of bias in human thinking that allows psychic cold readers to be successful, or gamblers to believe theyâ€™re winning when theyâ€™re losing money hand over fist.Â The human gaze is a powerful social tool, but itÂ doesn’tÂ extend to the realm of the supernatural.
Byline: This guest post is from Endre Rex-Kiss, an occasional guest blogger and freelance writer in topics ranging from green concepts to sustainable living. He currently represents Lenses Online, a popular online store of cheap contact lenses and contact solutions. Check out Endre’s rants on Twitter.