Would you trust this robot? It all depends on how well it is programmed to mimic the nonverbal gestures and tics that humans use to signal their trustworthiness. Yes, Nexi the Robot is cracking the code of why humans trust.

The robot is the focus of a study put together by psychologists, economists, and roboticists at a range of institutions, including Northeastern, MIT, and Cornell. They're hoping to isolate the nonverbal factors that encourage people to trust one another. The key, they believe, lies in programming Nexi to perform certain gestures while conversing with test subjects.

Northeastern psychology professor David DeSteno explains why this is crucial:

"People tend to mimic each other's body language, which might help them develop intuitions about what other people are feeling — intuitions about whether they'll treat them fairly."

In other words, although we're not consciously aware of it, our tendency to imitate the gestures and nonverbal cues of others gives us insight into their motivations and intentions. It's then a question of translating this information into an intuitive hunch as to whether the person we're talking to is as trustworthy as they say they are. If that's true, there should be specific gestures Nexi can do that will either maximize or minimize people's assessment of its trustworthiness.


The experiments to test this hypothesis are currently underway. The human test subjects are put in a room with Nexi and told to converse with her. What they don't know is that, for certain participants, Nexi is performing very carefully programmed gestures that the researchers believe will make humans more likely to trust the robot.

DeSteno outlines what they're hoping to accomplish:

"Using a humanoid robot whose every expression and gesture we can control will allow us to better identify the exact cues and psychological processes that underlie humans' ability to accurately predict if a stranger is trustworthy.

"The goal was to simulate a normal conversation with accompanying movements to see what the mind would intuitively glean about the trustworthiness of another. Trust might not be determined by one isolated gesture, but rather a 'dance' that happens between the strangers, which leads them to trust or not trust the other."

The true test of how much the humans trust Nexi to do the right thing comes when they play an economic game that's straight out of game theory. Called "Give Some", the humans have to decide how to split up a sum of money between themselves and Nexi, as well as how much they would expect Nexi to give them if it was the robot's decision. The early results are encouraging that the researchers are on the right track, and they plan to continue their work by testing whether Nexi can assess the trustworthiness of its human conversation partners.