In a social situation, eye contact with another person can show that you are paying attention in a friendly way. But it can also be antagonistic, such as when a political candidate turns toward their competitor during a debate and makes eye contact that signals hostility. Here's what hard science reveals about eye contact:

(41) 【C】Eye contact can be a friendly social signal.

We know that a typical infant will instinctively gaze into its mother's eyes, and she will look back. This mutual gaze is a major part of the attachment between mother and child. In adulthood, looking at someone else in a pleasant way can be a complimentary sign of paying attention. It can catch someone's attention in a crowded room.“Eye contact and smiles" can signal availability and confidence, a common-sense notion supported in studies by psychologist Monica Moore.

(42) 【E】Biological factors behind eye contact are being investigated.

Neuroscientist Bonnie Auyeung found that the hormone oxytocin increased the amount of eye contact from men toward the interviewer during a brief interview when the direction of their gaze was recorded. This was also found in high-functioning men with some autistic spectrum symptoms, who may tend to avoid eye contact. Specific brain regions that respond during direct gaze are being explored by other researchers, using advanced methods of brain scanning.

(43) 【G】Eye contact can be aggressive.

With the use of eye-tracking technology, Julia Minson of the Harvard Kennedy School of Government concluded that eye contact can signal very different kinds of messages, depending on the situation. While eye contact may be a sign of connection or trust in friendly situations, it's more likely to be associated with dominance or intimidation in adversarial situations. “ Whether you're a politician or a parent, it might be helpful to keep in mind that trying to maintain eye contact may backfire if you're trying to convince someone who has a different set of beliefs than you,” said Minson.

(44) 【A】Eye fixations are brief.

When we look at a face or a picture, our eyes pause on one spot at a time, often on the eyes or mouth. These pauses typically occur at about three per second, and the eyes then jump to another spot, until several important points in the image are registered like a series of snapshots. How the whole image is then assembled and perceived is still a mystery although it is the subject of current research.

(45) 【D】Personality can affect how a person reacts to eye contact.

In people who score high in a test of neuroticism, a personality dimension associated with self-consciousness and anxiety, eye contact triggered more activity associated with avoidance, according to the Finnish researcher Jari Hietanen and colleagues. “Our findings indicate that people do not only feel different when they are the centre of attention but that their brain reactions also differ." A more direct finding is that people who scored high for negative emotions like anxiety looked at others for shorter periods of time and reported more comfortable feelings when others did not look directly at them.