Is it OK to bully automated cars?

To integrate automated vehicles (AVs) into our transportation network, we should consider how human road users will interact with them. Human aggression toward AVs could be a new risk in mixed traffic and reduce AV adoption. Is it OK to drive aggressively toward AVs? We examined how identical aggressive behavior toward an AV or human driver is appraised differently by observers. In our 2 (scenario type: human driver vs. AV) × 2 (victim identity salience: low vs. high) between-subjects survey, we randomly allocated participants (N = 956) to one of four conditions where they viewed a video clip from an AV or a human driver showing a car suddenly braking continuously ahead of the AV or human driver's car. The salience of victim identity influenced the observers' appraisals of aggressive behavior. When asked to judge the front car's behavior toward this AV or human driver (the victim identity is salient), they reported more acceptability and less risk perception, negative affect, and immoral judgment while judging this behavior toward the AV. When asked to judge the front car's behavior (the victim identity not highlighted), they reported non-different appraisals. This finding implies that AVs might need to hide their identity to blend in visually and behaviorally as regular cars.