Science Daily reports on research conducted at Northwestern University that found infants could differentiate between water and a ‘faux water’ solid:
The finding that infants can distinguish between solids and liquids at such an early age builds upon a growing body of research that strongly suggests that babies are not blank slates who primarily depend on others for acquiring knowledge. That’s a common assumption of researchers in the not too distant past.
“Rather, our research shows that babies are amazing little experimenters with innate knowledge,” Susan Hespos said. “They’re collecting data all the time.”