For hundreds of years, nostalgia wasn’t just an emotion, but a potentially deadly disease. Coined by a Swiss physician in 1688, nostalgia struck down servants in 17th-century Germany and killed soldiers in their thousands during the American Civil War. It was a kind of pathological homesickness and while its exact mechanism is unclear, it caused people to slowly waste away. Weak and unable to eat, some starved to death.
These days, we view nostalgia very differently. Now, psychologists and neuroscientists think nostalgia is a predominantly positive, albeit bittersweet, emotion that arises from personally salient, tender, wistful memories of…
