Overt congruent facial reaction to dynamic emotional expressions in 9–10-month-old infants

• Published in: Infant behavior & development 2019-02, Vol.54, p.48-56
• Main Authors: Hashiya, Kazuhide, Meng, Xianwei, Uto, Yusuke, Tajiri, Kana
• Format: Article
• Language: English
• Subjects: Dynamic expression; Facial action coding system; Facial mimicry; Infant
• ISSN: 0163-6383; 1879-0453
• DOI: 10.1016/j.infbeh.2018.12.002

•Infants selectively show facial reactions to dynamic happy and angry facial expressions.•Infants’ congruent facial responses are enhanced during repeated observations.•Observable congruent facial reactions appear to be present in the first year of life. The current study aimed to extend the understanding of the early development of spontaneous facial reactions toward observed facial expressions. Forty-six 9- to 10-month-old infants observed video clips of dynamic human facial expressions that were artificially created with morphing technology. The infants’ facial responses were recorded, and the movements of the facial action unit 12 (e.g., lip-corner raising, associated with happiness) and facial action unit 4 (e.g., brow-lowering, associated with anger) were visually evaluated by multiple naïve raters. Results showed that (1) infants make congruent, observable facial responses to facial expressions, and (2) these specific facial responses are enhanced during repeated observation of the same emotional expressions. These results suggest the presence of observable congruent facial responses in the first year of life, and that they appear to be influenced by contextual information, such as the repetition of presentation of the target emotional expressions.