Contagious Crying Revisited: A Cross-Cultural Investigation Into Infant Emotion Contagion Using Infrared Thermal Imaging

Abstract

Contagious crying in infants has been considered an early marker of their sensitivity to others' emotions, a form of emotional contagion, and an early basis for empathy. However, it remains unclear whether infant distress in response to peer distress is due to the emotional content of crying or acoustically aversive properties of crying. Additionally, research remains severely biased towards samples from Europe and North America. In this study, we address both aspects by employing the novel and non-invasive method of infrared thermal imaging, in combination with behavioural markers of emotional contagion, to measure emotional arousal during a contagious crying paradigm in a cross-cultural sample of 10- to 11-month-old infants from rural and urban Uganda and the United Kingdom (N = 313). Infants heard social stimuli of positive, negative, and neutral emotional valence (infant laughing, crying, and babbling, respectively) and a non-social, acoustically matched artificial aversive sound. Results revealed that overall changes (as opposed to positive or negative) in infant nasal temperature were larger in response to crying and laughing compared to the artificial aversive sound and larger for crying than for babbling. Infants showed stronger behavioural responses for crying than for the artificial stimulus, as well as for crying than for laughing. Overall, our results support the view that infants within the first year of life experience emotional contagion in response to peer distress, an effect that is not just explained by the aversive nature of the stimuli. Sensitivity to others' emotional signals in the first year of life may provide the core building blocks for empathy.

Keywords: cross‐cultural; emotional contagion; empathy; infrared thermal imaging.

FIGURE 1

Experimental setup of the playback experiment featuring thermal camera and monitor. Images with permission.

FIGURE 2

Thermal recording of the infant's face and region of interest (circle at nose tip) for temperature extraction.

FIGURE 3

Playback trial sequence featuring baseline, stimulus, and recovery phase. Baseline showing cartoon without sound (10 s); stimulus presentation with moving bubbles background and audio overlay (60 s); recovery showing cartoon overlaid with calming instrumental music (30 s).

FIGURE 4

Behavioural markers of emotional contagion in infants in response to playbacks of crying and laughing, combining sites. The rating 0–3 indicates intensity of emotional contagion/congruent emotional markers, that is, negative affect in response to crying and artificial stimuli and positive affect in response to laughing stimuli. Violins show distribution of raw data, the white dot represents the median and the black bar represents the interquartile range. Asterisks represent significant effects (* p < 0.05, *** p < 0.001).

FIGURE 5

Behavioural markers of emotional contagion in infants in response to playbacks of crying. The rating 0–3 indicates intensity of emotional contagion/congruent emotional markers, that is, negative affect in response to crying and artificial stimuli and positive affect in response to laughing stimuli. Violins show distribution of raw data, the white dot represents the median and the black bar represents the interquartile range. Asterisks represent significant effects (* p < 0.05, *** p < 0.001) and artificial, combining sites.

FIGURE 6

Maximum nose tip temperature change by condition, combining sites. Violins show distribution of raw data, the white dot represents the median and the black bar represents the interquartile range. Asterisks represent significant effects (* p < 0.05, *** p < 0.001). The rural Ugandan site was Budongo, the urban Ugandan site was Mbarara.

FIGURE 7

Maximum nose tip temperature change by site, combining Conditions. Violins show distribution of raw data, the white dot represents the median and the black bar represents the interquartile range. Asterisks represent significant effects (* p < 0.05, *** p < 0.001). The rural Ugandan site was Budongo, the urban Ugandan site was Mbarara.