Science starts early.

Frank Kell reviews experiments that show that young children are often quite adept at uncovering statistical and causal patterns, and that many foundations of scientific thought are built impressively early in our lives. Infants make causal interpretations by integrating information in ways that closely mirror adults...certain sequences of events automatically elicit thoughts of causation at all ages. In addition to figuring out the causal relations underlying novel devices, children are also sensitive to highly abstract causal patterns associated with specific “domains” that correspond roughly to...biology, physical mechanics, and psychology.

...an infant learning language, upon hearing streams of syllables, not only has to notice how often certain syllables occur but also needs to infer higher-order patterns arising from those syllables. One study showed that 5-month-old infants can handle this challenge by rapidly tracking not only the sounds of the syllables but also visual patterns associated with each syllable. In the experiment, infants looking at a computer screen were repeatedly presented with abstract patterns of syllables and shapes. An “ABB” pattern, for instance, could be represented by certain shapes corresponding to the syllables “di ga ga.” When presented with a new pattern (ABA) with new syllables—such as “le ko le”—the infants looked longer at the shapes on the screen than if the new syllables were in the old ABB pattern. This suggests that they recognized it as a new, unfamiliar correlation...6-month-olds can take the next step and infer causation from certain kinds of correlations. In these experiments, researchers measured how long infants looked at animations showing “collisions” of shapes. In some animations, one object “launched” a second one, causing it to move, as when two billiard balls collide. When shown animations in which the balls reversed roles, infants looked longer at the new pattern than at the original one.

in thinking about biological phenomena such as disease or inheritance, children may make different inferences from patterns of covariation than they do for physical phenomena such as collisions or rotating gears. Another top-down expectation that children bring to living things, but not to artifacts, is an “essentialist bias”: the idea that something you can't see (e.g., “microstructural stuff ”) causes what you can see (“surface phenomena” such as feathers or fur) and is the essence of the thing being observed. This is a guiding principle in much of formal science, even as it can also lead to false inferences, such as that species are defined by fixed essences.