Building Better Human-Agent Teams: Tradeoffs in Helpfulness and Humanness in Voice

We manipulate the helpfulness and voice type of a voice-only agent teammate to examine subjective and objective outcomes in twenty teams with one agent and at least three humans during a problem solving task. Our results show that agent helpfulness, but not the humanness of the agent's voice, significantly alters perceptions of agent intelligence and trust in agent teammates, as well as affects team performance. Additionally, we find that the humanness of an agent's voice negatively interacts with agent helpfulness to flip its effect on perceived anthropomorphism and perceived animacy. This means human teammates interpret the agent's contributions differently depending on its vocal type. These findings suggest that function matters more than form when designing agents for effective human-agent teams and help to explain contradictory findings in the literature. Practitioners should be aware of the interactive effects of voice and helpfulness on subjective outcomes such as perceived anthropomorphism and animacy.