Love really is sweet! Both candy and water taste sweeter when people think about love, a new study has found.
However, jealousy fails to bring out bitter or sour tastes, despite metaphors that suggest it might, researchers said.
The finding that love alters one's sensory perceptions and jealousy does not is important to psychologists who study "embodied" metaphors, or linguistic flourishes that people quite literally feel in their bones.
For example, studies have shown that people induced to feel lonely rate the temperature of the room as colder than do their unprimed counterparts.
After seeing previous research on emotional metaphors, like the studies linking loneliness to coldness, Chan and his colleagues wanted to expand the question.
"We always say, 'love is sweet,' 'honey baby,' this kind of thing. We thought, let's see whether this applies to love," said researcher Kai Qin Chan, at Radboud University Nijmegen in the Netherlands.
Chan and colleagues conducted three experiments on 197 students at the National University of Singapore.
In the first two studies, researchers asked students to write about an experience either with romantic love or with jealousy, or about a neutral topic.
Next, scientists had the students taste either Ribena Pastilles (a sweet-and-sour gummy candy) or Meiji Morinaga bittersweet chocolates, 'LiveScience' reported.
After tasting the candies, the students ranked the treats' sweetness, bitterness and sourness. Those who had written about love ranked both candies as sweeter than those who had written about jealousy or a neutral topic.
However, writing about jealousy had no effect on rankings of bitterness, researchers found.
Researchers then asked 93 new student-volunteers to sample distilled water instead of candy. The students were told the water was a new drink product and they had to rate its sweetness, bitterness and sourness.
Love made the water taste sweeter while jealousy did not affect the water's taste, researchers found.
The finding is important for two reasons, Chan said.
"First of all, the fact that even water tastes sweeter when people think about love reveals that the emotion isn't acting on the taste receptors on the tongue, making them more sensitive to sugar. There's no sugar in the water, after all," Chan said.
"Instead, the effect must arise from the brain's processing of the taste information," Chan said.
"Second, the lack of an effect caused by jealousy reveals language alone doesn't influences the senses - metaphors have to go deeper," he said.
The study was published in the journal Emotion.
