Loneliness breeds wishful thinking, according to a new study that finds that eerily unrealistic faces seem more realistic to people when they feel isolated and alone.

People who are lonely see the "uncanny valley effect" — when a face looks almost, but not quite, lifelike — as more appealing than social butterflies do, according to the new research, detailed Sept. 5 in the journal Psychological Science.

"Even though two people may be looking at the same face, the point at which they see life and decide that person is worthy of meaningful social interaction may not be the same," Katherine Powers, a psychologist at Dartmouth College and one of the researchers on the study, said in a statement. [5 Ways Your Emotions Influence Your World (and Vice Versa)]

Freaky faces

People crave social connection, Powers said. In fact, social ties are so important that lonely people actually have worse health than those who have strong social connections. Humans also tune in to faces over other stimuli, which is part of the reason they also mistake rock formations on Mars for faces. Given that previous research has found that lonely people often fill their social emptiness by attributing humanlike traits to their gadgets or pets, Powers and her colleagues wondered if loneliness could affect the most basic social action: deciding whether someone is alive and human.

The researchers created a series of "morphs," mixing the face of a doll with the face of a real person. The images ranged from 100 percent doll to 100 percent human, with various mixtures of the two in between. First, 30 undergraduate participants viewed the faces one by one and rated them as "animate" or "inanimate." Next, the participants filled out a survey about their need to belong, which asked how strongly they agreed with statements like, "I want other people to accept me."

Facial morphs, from 0 percent human to 100 percent human, used to determine the point at which people declare a face to be animate versus inanimate. (Image credit: Katherine Powers, Andrea Worsham, Jonathan Freeman, Thalia Wheatley and Todd Heatherton, Psychological Science)

On average, people required the morphs to be 68.9 percent human before they'd dub them "animate." But people with a stronger need for social connections, as indicated by their responses on the survey, rated doll-like faces as animate more often than people with a less need, the researchers reported. The need for social connection explained 14 percent of the variation in people's thresholds for rating a face as alive.

Next, the researchers asked 49 different undergraduates to complete the same face-rating task. This time, instead of measuring the students' pre-existing need for social connections, the researchers manipulated that need. Half of the students were told that their futures would be isolated and lonely. The other half were told to expect lives full of stable, fulfilling relationships.

The students who were triggered to feel lonely and in need of connection rated more-inanimate faces as "animate" compared with the students triggered to feel socially connected. Induced loneliness lowered the threshold for declaring a face "alive" by 7 percent, Powers and her colleagues found.

Desperate for connection

Because social networks are so important to humans, lonely people may cast a wider net in the search for connections, the researchers concluded.

"I think the fact that we can observe such a bias in the perception of basic social cues really underscores the fundamental nature of the human need for social connection," Powers said. If someone is desperate to make those connections, they might benefit from lower standards for the people with whom they're trying to connect.

"Though refinement of these judgments may follow," the researchers wrote, "the initial perceptual bias we have demonstrated suggests that overattributing animacy may be a fundamentally adaptive strategy."

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