One recent study, published in the journal Emotion, asked participants to write about an experience of either romantic love, jealously, or a neutral topic, following which they were each given a sweet-and-sour or bittersweet candy. Those participants who wrote about love found the candies sweeter than their counterparts. Participants then repeated the experience, but were given water under the guise of ‘a new drink product’ rather than candy. Once again those who wrote about love found the water sweeter.
Fortunately for those who wrote about jealously, evoking the emotion did not cause the candies or water to taste bitter, as metaphor might suggest – showing that only some metaphors have truth.