AO1

• signs - proximity seeking, separation distress, secure-base behaviour, joy at reunion
• caregiver-infant interactions are the start of the development of attachment where the responsiveness of the caregiver to the infant's signals are key to the development of attachment
• reciprocity is where each person in a relationship responds to the other and elicits a response from them
• alert phases are awake phases where the baby signals that they are ready for interaction and occurs when babies lead reciprocity
• interactional synchrony is carrying out the same action simultaneously (imitation)