Normally associated with depression and sadness, researchers at the University of Southampton in England have found that the bitter-sweet emotion of longing in fact counteracts loneliness, boredom and anxiety.
The New York Times reports that: "It makes people more generous to strangers and more tolerant to outsiders. Couples feel closer and look happier when they're sharing nostalgic memories."
Nostalgia also physically warms us up.
Dr Tim Wildschut, senior lecturer at the University of Southampton and co-author of the study, said: "Our study has shown that nostalgia serves a homeostatic function, allowing the mental simulation of previously enjoyed states, including states of bodily comfort; in this case making us feel warmer or increasing our tolerance of cold."
The study has also shown that charities and not-for-profit organisations can benefit from nostalgic feelings, because it encourages people to donate more.
Wildschut said: "Nostalgia increases empathy-based charitable intentions and behaviours. It is encouraging to learn that people can mine their nostalgic memories and derive from this a feeling of empathy for the suffering of others."
The study also showed that most people experience nostalgia at least once a week, and nearly half experience it three or four times a week.
According to the New York Times, nostalgia had been considered a disorder ever since the term was coined by a 17th-century Swiss physician who attributed soldier's mental and physical maladies to their longing to return home - nostos in Greek - and the accompanying pain, algos.
