Conclusions
The present study highlighted a sexual dimorphism in the neonatal neural processing of affective touch, a social cue known to play a key role in the early foundation of lifelong socio-emotional wellbeing. Early sexual dimorphic brain development may support marked diversities in reproductive, parental, and social behavior later in life. As many of the observed brain responses to affective touch were subcortical, further fMRI studies including additional tactile stimuli and longitudinal designs are required to assess the sex-specificity of neural responses to socio-affective tactile stimulation and its implications for child development.