When looking at full brain scans they saw that lonely individuals have less grey matter in the left posterior superior temporal sulcus (pSTS)—an area implicated in basic social perception, confirming that loneliness was associated with difficulty in processing social cues.

“From the study we can’t tell if loneliness is something hardwired or environmental,” said co-author Dr Bahador Bahrami (UCL Institute of Cognitive Neuroscience). “But one possibility is that people who are poor at reading social cues may experience difficulty in developing social relationships, leading to social isolation and loneliness.”