Narrator: This is Science Today. Over the years, it's been discovered babies are more perceptive about the world than previously thought. Since 1982, psychologist Linda Acredolo of the University of California, Davis, has been studying how baby signs - or gesturing - affect cognitive development.

Acredolo: Over the course of these many, many, many years we have gathered data that very clearly demonstrate that baby signs promote learning to talk. Actually make it easier and promote good cognitive skills - actually affect I.Q. and most importantly to us and to the families, make the parent-child interaction much smoother and more positive.

Narrator: Using baby signs, Acredolo also discovered babies are capable of having a long-term memory.

Acredolo: So, the baby signs really is a window - not only for parents into the baby's mind, but also for researchers to find out more about what the developing mind is like than we were ever able to before.

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