Metaphor creates intimacy and temporarily enhances theory of mind.

In 3 experiments we show that, relative to reading literal sentences, reading metaphor enhances performance on the Reading the Mind in the Eyes Test (RMET), an instrument meant to measure first-order theory of mind. In each experiment participants read metaphorical or literal sentences in different contexts and afterwards completed an ostensibly unrelated task, the RMET. In Experiment 1, participants were presented metaphorical or literal sentences in short discourse contexts and were asked questions about the characters in the stories. We found that when one of the characters used metaphor, they were rated as having a closer relationship. A novel finding is that the degree to which the characters are perceived as being more intimate in the metaphor condition, the higher their scores on the RMET. In Experiment 2, participants created fictive contexts to prompting literal or metaphorical sentences. This writing task was followed by the RMET. Participants who created contexts for the metaphors scored significantly higher on the RMET. In Experiment 3, participants read metaphors or literal counterparts without any discourse contexts. Once again, participants scored higher on the RMET after reading metaphorical as opposed to literal sentences. Additional analyses across the 3 experiments revealed that metaphors but not literal counterparts were associated with fictive contexts that contained reference to mental states and idioms with emotional content (Experiment 2), were associated with a sense of intimacy between interlocutors (Experiment 1), the presence of affective words in the created context (Experiment 2), and association with a human agent when context was not presented (Experiment 3).