Instructions
Look at the doll's eyes. Chatty Cathy dolls have sleepy eyes in one of three versions: decal, pinwheel and glassine. The pinwheel and glassine eyes are set into the doll's head and have a sparkle to them, while the decals appear painted on.
Check the speaker in the chest. Authentic Chatty Cathys will have either a piece of fabric covering the speaker or holes drilled into the chest in a hexagon shape. Dolls with fabric chests are prototype versions made in 1959 and 1960.
Look at the doll's back. 1959 prototype Chatty Cathys have no markings on their backs, but 1960 prototypes have a stamp that says "Chatty Cathy, Patents Pending," along with the Mattel logo.
Pull the string and listen to the doll's phrases. Chatty Cathy dolls said either 11 or 18 phrases, among them, "I love you," "Let's play house," "Let's play school," "I'm hungry," "I hurt myself," and "May I have a cookie?"
Check the doll's hairstyle. Chatty Cathy's hair was most frequently styled in a chin-length bob, although others had pageboy and pigtail styles.