Eye contact is a tricky business, something that feels a lot easier to screw up than it does to get right. The conventional wisdom holds that it’s more or less an unqualified good thing — holding someone’s gaze can make you seem more empathetic, more trustworthy, and more likable, and also makes it more likely that whomever you’re speaking to will remember what you say. Besides, avoiding eye contact comes off as creepy.
On the other hand, though, so does a prolonged, unwavering stare. And social-science research is littered with eye-contact caveats: One 2013 study, for example, found that when you hold a person’s gaze for too long, it can make the other person more resistant to what you’re saying, like you’re trying to stare them into agreement. And some research suggests that, contrary to popular belief, extended eye contact may be the mark of someone who’s telling a lie.
So, to sum up: Eye contact can be good, and also bad, and there’s some Goldilocks-approved sweet spot in between too much and too little where you come off just right. Which is good to know in theory, but not really all that helpful in practice unless you know what that sweet spot looks like.
Luckily, in a study recently published in Royal Society Open Science, a team of British psychologists claim to have figured it out: On average, the ideal length of eye contact — enough that you don’t seem shifty, but not so much that you’re creepily intense — is 3.3 seconds.
The study subjects were 498 visitors to the London Science Museum, ranging in age from 11 to 79. After taking a personality test, the participants watched video clips of an actor staring directly into the camera (giving the illusion of eye contact with the viewer) for varying amounts of time, punctuated by brief moments of looking down, and were told to press a button when the eye contact felt uncomfortable, either because it went on for too long or because it ended too quickly. (Their preferences, it’s also worth noting, didn’t change depending on how the subjects felt about the person in the video — after the clips were over, the researchers asked them to rate the actors on attractiveness, dominance, trustworthiness, and how threatening they appeared.)
Here’s one of the videos:
At the same time, the study authors used eye trackers to monitor where their subjects were looking and when their pupils dilated (it’s something that always happens during eye contact, though it can occur at different speeds). The people who indicated that they liked to hold eye contact for longer, the researchers found, also had pupils that dilated more quickly upon first meeting the other person’s gaze — illustrating, they wrote, that “that a person’s preferred duration of eye contact is signalled by physiological indices … beyond volitional control.”
It’s an interesting tidbit, though for practical purposes, not an especially useful one. As Science reported, “the differences are so subtle … that they can only be seen with the eye-tracking software — making any attempts to game the system likely to end up awkward rather than informative.” In other words, please do not try to figure out when your conversation partner’s pupils are getting bigger, both because you can’t and because it would require you to violate all the norms of personal space. Just lock eyes for however long feels natural. As long as natural is somewhere around 3.3 seconds.
But even that magic number isn’t really a lifeline for those struggling through the eye-contact minefield — next time you have a conversation, try counting up intervals of 3.3 seconds in your head. Bet it doesn’t make things any smoother. It may just be better to read the study findings as an interesting quirk of human nature, accept that some things cannot change, and then return to our awkward ways. And avoid long hallways.