Joint attention is vital to language development and early word learning. It refers to the shared attention between two people and a third object or event. The attention shifts between the object and the other person, and both persons are aware that attention to the third object is shared. Joint attention is shown through alternating gaze between the object and another person, eye contact, and sometimes accompanied with gestures (such as pointing), speech, sign language, or PECS (picture exchange system).

An example of joint attention is story time at school, when children sit down in a circle to listen to the story being read, looking at the teacher as she reads, then looking at the pictures in the book as they are shown to the class, and back to the teacher as she continues to read the story.