The Visual Cliff Study

The Visual Cliff Study

My all-time favorite study in the field of developmental psychology is the visual cliff.  Depth perception is such an important part of survival that it might be programmed into our DNA.  After all, our ancestors who walked off the edge of a cliff didn’t get to reproduce very much.  So researchers wanted to see if babies already demonstrated depth perception when they started crawling around in the latter part of the first year.

They set up a big table with a large sheet of plexiglass on it that extended far beyond the edge of the table.  That way, when a baby crawled to the edge of the table, visually there would be a cliff, but the plexiglass would prevent the baby from falling over the edge.  They got a bunch of newly-crawling babies and had their mothers beckon them to the edge of the table.  When the babies got to the edge of the table, would they sense danger, turn around and go back?  Or would they just keep crawling past the edge?

I like to refer to newly-crawling babies as being in the sophomore period of life.  The word “sophomore” comes from two Greek words, “sophos” meaning smart (like in sophisticated) and “moros” meaning stupid (as in moron).  So if you’re a sophomore, you are both smart and stupid at the same time.

As it turned out, 80% of the babies, even with their mothers beckoning them, stopped at the edge, turned around, and went back.  Smart babies.  But then the videotapes were examined very closely.  What was noticed was that 75% of those babies, as they were turning around to go back, actually placed their center of gravity over the edge of the table.  So if the plexiglass wasn’t there, they would have gone splat.

An active infant may be smart enough to sense danger, but unfortunately, at this early stage of development, she may not be able to avoid it.

Dr. Mike

Michael K. Meyerhoff, Ed.D. (a.k.a. “Dr. Mike”) is a member of the management team at Romp n’ Roll.  After receiving his bachelor’s degree in psychology from Columbia University, he earned his master’s and doctorate degrees in human development from the Harvard Graduate School of Education, where he also held a position as a researcher with the Harvard Preschool Project.  He may be contacted via e-mail at