Mirrors and cause-effect toys

Cause-and-effect toys are the highest-value category from 4 months on. Rattles that make sound when shaken, crinkle books that respond to grip, and press-a-button-hear-a-sound toys teach baby that their actions produce outcomes — the foundation of problem-solving. Position toys just within reach, not in the way. Baby swipes, sometimes misses, sometimes hits. When they hit, react — clap, laugh, mirror it back. The social response amplifies the learning. Avoid toys that light up and sing without any input required. Passive entertainment doesn't build the cause-effect wiring. The best toys respond only when baby acts on them and then stop until baby acts again.