Rough-and-tumble play rough-and-tumble play components and non-play social interactions across play sessions. The following data are pooled for genotype of the cage mate. The total time spent playing across each individual play session depending on the genotype of the first play partner in (A) WT-WT, (A’) HET-HET, (A”) HET-WT and (A”’) WT-HET female pairs. The total time spent engaged and exemplary images for specific rough-and-tumble play components depending on genotype of the first play partner in female pairs of WT-WT (Dark purple circles), HET-HET (Purple boxes), HET-WT (Green diamonds) and WT-HET (Dark green triangles) for (B) pinning, (B’) wrestling, (B”) chasing and (B”’) nape attacks. (C–C”’) Non-play social interactions. (C) Total averaged time spent in non-play social interactions across all play session in pairs of female WT-WT (Dark purple bars, N = 20), HET-HET (Purple bars, N = 20), HET-WT (Light green bars, N = 20) and WT-HET (Dark green bars, N = 20). The total time spent averaged across play sessions in non-play social interactions with a (C’) same- or (C”) opposite genotype play partner in pairs of female WT-WT (Dark purple bars, N = 10), HET-HET (Purple bars, N = 10), HET-WT (Light green bars, N = 10), and WT-HET (Dark green bars, N = 10). (C”’) The sequence comparison of time spent in non-play social interactions depending on genotype of the first play partner in female pairs of WT-WT (Dark purple circles), HET-HET (Purple boxes), HET-WT (Green diamonds) and WT-HET (Dark green triangles). Data are presented as mean + SEM. *p < 0.05.