The still-face interaction paradigm
An experimental task was introduced in 1978 to prove that infants actively contribute to social interaction. It is called the Still-Face Paradigm or SFP.
In the experiment, 3 phases of face-to-face interaction of infants with an adult were tested: the normal interaction, the still-face (where the adult becomes unresponsive and maintains a neutral facial expression), and a reunion where the adult resumes normal interaction.
Indeed, the still-face paradigm showed effects like increased gaze aversion and less smiling.
