It’s a treat when the grandkids come to visit – but it’s also lovely when they go home again. Social contact is important to everybody’s wellbeing but older people in particular need periods of solitude afterwards to recharge their batteries. Researchers at the University of Zurich studied 118 people over 65 living in German speaking regions of Switzerland. Participants used an app to log the duration of spoken social interaction. All other time, including sleep, was considered solitude. They found a relationship between the length of the former and that of the latter. Though they admit their work had limitations, it suggests older people regulate time spent in solitude or interacting with others “according to shifts in the levels of their need to belong and their need to conserve energy”.