In December 1953, science writer Isaac Asimov was thumbing through a copy of a 1932 issue of Time magazine when he saw a drawing of a mushroom cloud caused by a nuclear explosion. A closer look revealed that the drawing was actually of the Old Faithful geyser in Yellowstone National Park in the US. The mix-up got Asimov thinking about the implications of a magazine from 1932 carrying a drawing of an atomic cloud. Many more meanderings of the mind later, he came up with the plot of a time travel story, which was introduced to the world in 1955 as The End of Eternity.
In science fiction, you can’t believe anything you see. But fact, as we’re constantly told, is stranger than fiction, and seeing is believing, in real life. Even if what you see, or think you see, is actually not what you see at all. We could be talking about moral or societal issues. But we’re not: this is a completely different dish of food for thought.
You would think by the time you’re old enough to procreate, vote, marry (not necessarily in that order), you’d know your body well enough to tell when it is looking for nourishment. Turns out, you’d be wrong. Researchers in the UK recently divided up a hundred students in their 20s in groups, and showed them either a small serving of tomato soup or a larger serving. The students were then handed the bowls of soup and invited to sit down and eat. While they were eating, the researchers secretly changed the amount of soup in their bowls through a concealed tube. Some had half the content of their bowl pumped out; others had their bowls replenished. As a result, some students who had been shown a bowl containing some 500 ml of soup actually got only 300 ml; others who had viewed a bowl containing 300 ml of soup actually consumed almost double that amount. None of them twigged to the truth.
The students’ hunger levels were measured immediately after they finished their meal. The answers were bang on target: each student answered accurately, the response based on the actual amount he or she had eaten. However, when questioned again a few hours later, the story changed. Now, the students who had seen the larger portion but really eaten only the smaller amount reported being much fuller than those who had originally seen the smaller portion but actually consumed a lot more.
Remember when doctors told us that our food intake was influenced by visual cues and ambience? That people who dined while watching TV or reading a book ended up consuming more than those who solely focused on their food? And that eating with a fat person (who’s presumed to be indiscriminate about what he tucks into) liberated us from watching what we ate—as if we’re embarrassed to eat whole-heartedly when sitting with thin people (who are perceived as delicate eaters).
The latest finding reiterates the importance of visual clues. It tells us that it’s not our stomach that dictates how much we eat, but our short-term memory. People’s hunger levels are evidently predicted not by how much they ate at their last meal, but by how much food they remember seeing themselves eating. It’s almost as if our memory is distinct from our body.
Or maybe it’s just that Grandma was right. Our eyes are bigger than our stomach.