Raise a Friendly Baby

Introduce Her to Older Kids

If you've ever seen a baby stare rapturously at an older sibling, you know: Infants love big kids. "A baby's first smiles and laughs often come from watching an older brother or sister," says K. Mark Sossin, PhD, professor of psychology at Pace University in New York City. Big sibs provide a constant source of inspiration for milestones like walking, eating, and talking, and their silly sense of humor also appeals to babies. If your infant is a firstborn, then a cousin, neighbor's kid, or family friend may have a similar effect.

When Casey Hennigan was 7 months old, she was the youngest member of her daycare group. That meant she hung out with 1-year-olds every day. "She loved watching them and tried to do everything they did, like standing, even though she wasn't quite ready," says her mom, Kelly, from Cherry Hill, New Jersey.