Picking up nuances of facial expression is a crucial part of frontline employee–guest interaction, yet little is known about its neurocognitive mechanism. We use a neuroimaging approach to explore the individual differences in cognitive processing style of front-of-house (FoH) employees by comparing their brain structures with those back-of-house (BoH). A voxel-based morphometry analysis of 63 senior hotel executives’ brain images reveals that the grey matter volume in the occipital and fusiform face areas of FoH employees is greater than that of BoH employees and does not depend on the length of frontline experience. These regions have been implicated in facial expression recognition that is critical to the success in frontline roles. Our findings support the social brain hypothesis. To support sophisticated social cognition, resources are diverted to brain development associated with facial expression recognition. This development trajectory follows deferred adaptation, rather than conditional adaptation, proposed in developmental evolutionary psychology.