Our friends don’t just make us happier, they can make us healthier. Researchers from the University of Oxford found that the link between the number of friends and the ability to tolerate pain is due to the higher levels of endorphins in the body, the naturally produced feel-good chemicals that trigger a sense of wellbeing.

Friends bring benefits later in life, too. The rate of global cognitive decline in socially active senior adults was reduced by an average of 70% compared with those who socialised less often. Going it alone is now recognised as a real and quantifiable threat: “Lacking social connections carries the same risk for premature mortality as smoking 15 cigarettes a day, and exceeds the risk associated with obesity and physical inactivity,” explains Julianne Holt-Lunstad, Professor Psychology and Neuroscience, Brigham Young University.