Narrator: This is Science Today. It seems babies and toddlers are hard-wired to be attracted to glossy, reflective surfaces. Psychologist Richard Coss of the University of California, Davis says this innate sense is a holdover from when early primates sought water for survival.

Coss: Detecting water was absolutely essential, whether it’s a reflective surface or the sparkle that might occur when wind is blowing against the water. And of course, we have very sensitive sparkle detectors because they use these in psychological research with little flashing lights and even in young infants, your attention is attracted to something that glistens or just gives a little flash of light. So that’s probably capturing some of this natural property of water detection.

Narrator: Coss’ research of infants’ reactions to textures and patterns identified another ancestral holdover – a wariness of python and leopard patterns.

Coss: We have six-month old infants showing signs – not being fearful – but just of caution. So it’s possible we could think of textures that you could use for ringing the edges of pools, so children pause or maybe don’t go into the pool directly.

Narrator: For Science Today, I’m Larissa Branin.