Figure 3.

(A) Overall (r) and partial correlations (r_p) between the intensity of smiles, eye constriction, and mouth opening; and between the intensity of cry-faces, eye constriction, and mouth opening. Frames of video in which neither smiles nor cry-faces occurred (zero values) were randomly divided between the smile and cry-face correlation sets to maintain independence. (B) R², r, and r_p from regressing affective valence ratings on the intensity of smile/cry-faces, eye constriction, and mouth opening. All statistics represent mean values across infants. P values reflect two-tailed, one-sample t-tests of those values: * p < .05, ** p < .01, *** p < .001, **** p < .0001.