Pat, Pinch, or Poke Toddlers bite, hit, grab, and pull hair. By age 4 or 5—as a result of brain maturation, theory of mind, emotional regulation, and interactions with caregivers—children are more aware. Some, like the girl in the photo on the left, are deliberately prosocial, while others, like the boy in the photo on the right, are deliberately antisocial.
LIZ BANFIELD/GETTY IMAGES
MATTHIAS STOLT/GETTY IMAGES
MATTHIAS STOLT/GETTY IMAGES