In natural settings, people decide not only when to request information, but also which attribute of a situation to inquire about. Little is known about how participants prioritize inquiries about task-relevant features. We show that, in a new task of information demand, participants inefficiently inquired about attributes that had high individual value but were less informative about a total payoff, and these inefficiencies persisted in instrumental conditions in which they entailed significantly lower rewards. Factors contributing to inefficient information demand included a form of anticipatory utility motivated by high value individual attributes rather than the total reward, and difficulty identifying the most informative observations. Across participants, more efficient inquiries were associated with personality traits, including lower extraversion and reward sensitivity scores and higher stress tolerance and need for cognition. The results highlight new affective, cognitive and personality factors involved in prioritizing sources of information.