This work investigates the effects of personality expression and embodiment in conversational agents. We extend a personality-driven conversational agent framework by integrating LLM-based conversation support to provide information about contemporary scientific topics. We describe a user study built on this system to evaluate two opposing personality styles using three models: a dialogue-only model that conveys personality verbally, an animated human model that expresses personality only through dialogue, and an animated human model expressing personality through dialogue and expressive animations. The users perceive all models positively regarding personality and learning outcomes; however, models with high personality traits are perceived as more engaging than those with low personality traits. We provide an analysis of personality perception, learning, and user experience.

Immersive virtual environments populated by real and virtual humans provide valuable insights into human decision-making processes under controlled conditions. Existing literature indicates elevated comfort, higher presence, and a more positive user experience when virtual humans exhibit rich behaviors. Based on this knowledge, we conducted a web-based, interactive study, in which participants were embodied within a virtual crowd with complex behaviors driven by an underlying psychological model. While participants interacted with a group of autonomous humanoid agents in a shopping scenario similar to Black Friday, the platform recorded their non-verbal behaviors. In this independent-subjects study, we investigated behavioral and emotional variances across participants with diverse backgrounds focusing on two conditions: perceived agency and the crowd’s emotional disposition. For perceived agency, one group of participants was told that the other crowd members were avatars controlled by humans, whereas another group was told that they were artificial agents. For emotional disposition, the crowd behaved either in a docile or hostile manner. The results suggest that the crowd’s disposition and specific participant traits significantly affected certain emotions and behaviors. For instance, participants collected fewer items and reported a higher increase of negative emotions when placed in a hostile crowd. However, perceived agency did not yield any statistically significant effects.