Powered by artificial intelligence (AI), autonomous vehicles (AVs) are one of the most disruptive technologies to reduce road incidents, improve road efficiency and enhance mobility for underserved populations. However, existing literature of AV adoption is either based on descriptive analysis or simple applications of conventional behavioral frameworks. Drawing on behavioral reasoning theory (BRT), we examine the effect of reasoning process on consumers' attitudes and intentions toward adopting AVs, and how their psychological traits moderates the relationships. By conducting a nationwide survey in China (n = 849), we identify positive (negative) effects of individuals' reasons for (against) adopting AVs on their adoption intentions for AVs, and positive influence of face consciousness on the reasoning process. More importantly, we find that the psychological trait of need for uniqueness strengthens the association between consumers' reasoning for AVs and their adoption intention, while the risk aversion trait intensifies the negative relationships between consumers' reasoning against AVs and their attitude/adoption intention. We contribute to the literature of AI adoption by establishing the important roles of consumers' reasons for and against such innovations. We also extend the BRT framework by identifying the roles of psychological traits in moderating the relationships among reasoning, attitude, and adoption intention.