Left cheek bias for emotion perception, but not expression, is established in children aged 3–7 years

ABSTRACT

As the left hemiface is controlled by the emotion-dominant right hemisphere, emotion is expressed asymmetrically. Portraits showing a model's left cheek consequently appear more emotive. Though the left cheek bias is well established in adults, it has not been investigated in children. To determine whether the left cheek biases for emotion perception and expression are present and/or develop between the ages of 3 and 7 years, 145 children (71 male, 74 female; M age = 65.49 months) completed two experimental tasks: one assessing biases in emotion perception, and the other assessing biases in emotion expression. Regression analysis confirmed that children aged 3–7 years find left cheek portraits happier than right cheek portraits, and age does not predict the magnitude of the bias. In contrast when asked to pose for a photo expressing happiness children did not show a left cheek bias, with logistic regression confirming that age did not predict posing orientations. These findings indicate that though the left cheek bias for emotion perception is established by age 3, a similar bias for emotion expression is not evident by age 7. This implies that tacit knowledge of the left cheek's greater expressivity is not innate but develops in later childhood/adolescence.

KEYWORDS:

• Face perception
• emotion
• expression
• development
• asymmetry

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1 To rule out the possible confound of children's image selections in the Emotion Perception task being influenced by the side of screen on which the image was presented, we coded each trial according to the side of the screen on which the image the child selected appeared (left side, right side). Analysis confirmed that the side of screen on which the selected image was presented did not differ from that expected by chance (i.e. 50:50): t (144) = 0.717, p = .474.