Children are unable to recognize that their immediate hunger and thirst affects their choice of what they would want to eat or drink in the future, a Brock University study has found.

“If they’re thirsty, it’s probably not a good time to ask a child about what they’re going to eat tomorrow, because they’re going to be focused on the thirst,” psychologist Caitlin Mahy says of her study, “Young Children Have Difficulty Predicting Future Preferences in the Presence of a Conflicting Physiological State.”

Mahy’s work built upon on an earlier study in which researchers asked children if they would want to eat pretzels or drink water at that moment.

Mahy also asked the children in her study the same question. Regardless of how they answered, she gave the children the chance to eat as many pretzels as they wished, read them a story for five minutes and asked them the question: “I want you to imagine that you’re coming back tomorrow. What will you want tomorrow, pretzels or water?”

“You’d expect, based on children’s original baseline preference for pretzels, that they should be able to think ahead and say, ‘Well, even though I might be thirsty right now, tomorrow I’ll probably want pretzels again’,” explains Mahy.

But the children overwhelmingly chose water over pretzels as what they identified as what they would want the following day.

Mahy replicated the experiment in a group of three to seven-year-olds at Brock University and found that, like the earlier study, most children who chose pretzels over water initially indicated that they would want water the following day.

But, “there’s a possibility that the children were just bored with the pretzels so it wouldn’t matter what you’d give them: pretzels and chocolate or pretzels and broccoli,” says Mahy. “They may be thinking, ‘I just ate a bunch of pretzels, I’m sick of them’.”

So to rule out that possibility, Mahy added something new in her research: she asked the children to explain their choice of water over pretzels.

Mahy created four categories of possible answers: “current state,” where children could explain that they would want water tomorrow because they are thirsty now; “future state,” where children say that they would want water tomorrow because they might be thirsty; “general preference,” where children would that water is healthy or good for you; and an “other” category of unusual or miscellaneous responses.

Children’s answers fell in the four categories with equal regularity, says Mahy.

“It doesn’t seem to be that children are aware that, ‘I’m thirsty, that’s why I want water tomorrow’,” she says. “Their current state (of being thirsty) is so salient and obvious to them that they’re thinking, this is how I’m going to feel tomorrow and the next day and unable to separate how they’re currently feeling and inhibit that.”

To further prove the point, Mahy then gave the children some water to drink and asked them again if they would want pretzels or water the following day.

Most of them switched their preference from water back to pretzels.

“After their thirst was quenched, they were much more able to say, ‘Oh, I want pretzels because I love pretzels; they are good, they are tasty’,” says Mahy.

There was another interesting twist to the research results.

“You might expect that kids, by the time they are six or seven, are getting better at this than a three-year-old; you could not imagine a three-year-old saying, ‘I’m thirsty now so I’ll always be thirsty in the future’,” says Mahy.

“There was no difference between three- and seven-year-olds” in terms of whether they chose pretzels or water for the future or how they explained their future preference for water over pretzels, she says.

Mahy explains that adults even have a tough time with this.

“I often have this problem,” she notes. “I’ll eat breakfast and I’ll leave the house to run errands and think, ‘Oh I’m full right now, so I’ll be fine.’ And then it gets to be lunchtime and ‘I’m starving, and wondering what was I thinking’?”