When kids incessantly ask "Why?," mess around in the dirt and run their hands over everything within reach, they're not just being kids. It turns out they're also being scientists.
Until recently, preschoolers were widely believed to be irrational thinkers. For most of the 20th century, the prevailing theory pioneered by cognitive development expert Jean Piaget held that children roughly ages 2 through 7 cannot understand concrete logic or other people's perspectives.
Although young children are the only ones who truly know what they ponder, research conducted over the past decade has led many psychologists to see infants and toddlers as, in fact, capable of thinking logically and abstractly.
"The main thing is that they're drawing conclusions from data and evidence and experiences the same way scientists are - by making hypotheses, testing them, analyzing statistics and even doing experiments, even though when they do experiments, it's called 'getting into everything,' " said Alison Gopnik, a UC Berkeley psychology professor and one of the field's leading experts.
Better understanding of how children learn about the world could have important implications for their formal schooling, Gopnik argued in a recent paper published in the journal Science, which summarized studies by her and other researchers.
Kids don't have to wear lab coats to act like scientists, Gopnik said.
Teaching can backfire
In one study, Gopnik and her colleagues showed children ages 3 through 5 a machine with a switch on one side and two disks that spun on top.
By playing with this simple device, the preschoolers were able to figure out and distinguish between the many ways it worked: The switch made one disk spin, which made another disk spin; the switch made both disks spin; and so on.
In another of Gopnik's experiments, 4-year-olds were able to figure out how to make a toy light up in just two steps instead of several. But "they only did that if the (researcher) said, 'I don't know how this toy works,' " Gopnik said. "If the (researcher) said, 'This is my toy, I'll show you how it works,' they just imitated whatever the experimenter did."
In other words, children who were led rather than turned loose didn't devise the more creative solution - an "example of how, ironically, direct teaching ... can sometimes sort of backfire," Gopnik said. "It leads to a kind of narrowing of what children are thinking about, instead of an extension or broadening of it."
Other studies show that young children, in addition to being able to ponder their own actions, are also capable of weighing the actions of others.
That was the heart of a 2010 experiment involving rubber frogs and ducks run by Tamar Kushnir, an assistant professor of child development at Cornell University.
Social, statistical cues
In the study, 3- and 4-year-olds rummaged through boxes with either mostly toy ducks and a few toy frogs, or mostly toy frogs and a few toy ducks. After an adult picked up ducks from a frog-dominated box, the children were asked to choose one of the two animals to give to the adult. The children generally chose the duck, inferring based on statistical odds that the adult preferred ducks over frogs, the researchers said.
"The amazing thing is that children didn't just pay attention to what you were picking and why you liked it," Kushnir said. "They paid attention to what you left behind."
The study demonstrates that by an early age, children can already pick up on all kinds of social and statistical cues, Kushnir said.
"We know other people think and feel and want and know, and might have different perspectives from our own and different ideas from our own ideas," she said. "These are the different kinds of things children have mastered by age 4 or 5. That's remarkable."
Bennett cited a patient of hers, a boy, who recently stacked big pieces of foam into an arrangement that he called the letter "T."
The freedom to play and imagine "allows them to really use their mind and look at things from their perspectives and make their own judgments and scientific thoughts, even though it may not look like science to us," she said.
Overall, experts say, there are plenty of studies that make the case for educating very young children by focusing more on imaginative play - and less on traditional reading, writing and arithmetic.
"The most important lessons children learn early in life," Kushnir said, "don't happen in a classroom."