Fig. 1. Mice display prosocial comforting behavior.

a, Schematic of prosocial interaction assay. b, Example raster plots showing allogrooming and self-grooming during prosocial interaction. c, Time-courses of cumulative allogrooming duration of subjects and partners after partners experience foot-shocks. Mean ± s.e.m. d–h, Total duration (d), onset latency (e), total bout number (f), and average per-bout duration (g) of allogrooming and total duration of self-grooming (h) exhibited by subjects interacting with unstressed (control) or foot-shocked partners. i, j, Total allogrooming duration and total number of social approaches toward subjects exhibited by unstressed or foot-shocked partners. k–n, s, t, Total allogrooming duration of subjects and partners after partners experience forced swim (k, l) or acute restraint (m, n), or after odor transfer from a naïve or stressed donor to partners (s, t). o, Schematic of CNN-RNN framework for classifying behaviors. p, q, Performance of binary (p) and four-way multi-class (q) classification of allogrooming, sniffing, self-grooming, or other behaviors. r, t-SNE visualization showing separation of different behaviors based on spatiotemporal features. u, v, Evaluation of stress-relieving effect of prosocial interaction using the open field test. Heatmaps show partners’ average occupancy at different locations. w, x, Fraction of time partners spent in corners of the open field. In b-x, subjects are males; see Extended Data Fig. 1 for female subjects. Boxplots: median, quartiles, 1.5× interquartile range (IQR) and outliers. ***P < 0.001, **P < 0.01, *P < 0.05. For details of statistical analyses and sample sizes, see Supplementary Table 1.