As humans and robots work more often alongside one another, it’s increasingly important that we understand how trust flows between them both. A new study from the University of Michigan found that humans are less forgiving of robots after multiple errors and regaining their trust is difficult.

Just like human coworkers, robots can make mistakes that erode trust. The study explored four strategies to restore trust, including apologies, denials, explanations, and promises of trustworthiness.

The experiment involved 240 participants working with a robot colleague on a task, with the robot occasionally making errors and then offering a repair strategy. The results showed that after three mistakes, none of the repair strategies were able to fully restore trust.

Lost trust

“By the third violation, strategies used by the robot to fully repair the mistrust never materialized,” the researchers explain.

The research shows that more effective strategies need to be programmed into robots so that they can repair trust after they make mistakes. Additionally, robots must ensure they have mastered a new task before attempting to rebuild trust with humans.

“If not, they risk losing a human’s trust in them in a way that can not be recovered,” the authors continue. “Our study’s results indicate that after three violations and repairs, trust cannot be fully restored, thus supporting the adage ‘three strikes and you’re out.’”

The researchers explain that even if a robot improves after making a mistake, it may not be given a chance to demonstrate its improvement, resulting in the loss of its benefits. They point out that people may try to circumvent or ignore the robot, causing its performance to decline, potentially leading to termination due to poor performance or non-compliance.