We often greet our fondest memories with whimsy and longing — putting our follies of youth on replay to relieve the stressors of adulthood and soothe the aches and pains of a life punched up with deadlines. This nostalgia is good for us in more ways than one, research shows. Reminiscing helps us feel better about the present and more hopeful about our future.

A wealth of knowledge has arisen in recent years speaking to the idea that nostalgia has psychological and physiological benefits. Not only does nostalgizing, as the researchers call it, help us feel physically warmer when we do it; we also feel more hopeful about our futures and emotionally closer to those around us.

"Nostalgic stories often start badly, with some kind of problem, but then they tend to end well, thanks to help from someone close to you," said Dr. Constantine Sedikides, professor of social and personality psychology at the University of Southampton. "So you end up with a stronger feeling of belonging and affiliation, and you become more generous toward others."

From The Beginning

Nostalgia first began in the late 17th century as a pathological disorder, one that manifested itself in those maladapted to the present and afraid of the future.

Military physicians speculated that its prevalence among Swiss mercenaries abroad was due to earlier damage to the soldiers' ear drums and brain cells by the unremitting clanging of cowbells in the Alps, the New York Times reports. The word comes from the Greek nostos, meaning homecoming, and the accompanying pain, algos.

It was through Sedikides' and his colleagues' studies that they found nostalgia to be a worldwide phenomenon, with roots in the emotional and physical, but not pathological. Children as young as seven were nostalgizing, looking back fondly on birthday parties and vacations, the researchers discovered.

"The defining features of nostalgia in England are also the defining features in Africa and South America," said Dr. Wildschut, a colleague of Sedikides. People in their research consistently placed themselves in the spotlight of their nostalgia. They clicked the Viewmaster in their mind's eye and watched an event replay over and over, reporting the same emotions as when it first happened.

To test the strength of nostalgia, Southampton researchers conducted a study where participants read a story about natural disasters. The researchers hoped to induce negative emotions and, subsequently, loneliness. The results ended up confirming their hypothesis; people turned to nostalgia in order to cope with their newly depressed moods, and over time their mood elevated, making them feel less lonely.

Not Always Pretty

Of course, we all have storied pasts. These are the memories that we wish we could forget. They turn nostalgia against us. Instead of looking back on those times with fondness, we look upon them with regret or melancholy. But nostalgia isn't a totally double-edged sword. Researchers say the positive sides unquestionably bear the sharper edge.

"Nostalgia serves a crucial existential function," said Dr. Clay Routledge, associate professor of psychology at North Dakota State University. "It brings to mind cherished experiences that assure us we are valued people who have meaningful lives. Some of our research shows that people who regularly engage in nostalgia are better at coping with concerns about death."

It's for this reason that nostalgia reflects a larger concept for many researchers than simply remembering the past, or what we typically call "reminiscing." Cheeriness about the future alone holds little weight for the elderly or infirm. Looking back on the past and recalling what made life worthwhile are what affect present-day attitudes, even if those attitudes have no future to walk into.

"Many other people," explained Sedikides, "have defined nostalgia as comparing the past with the present and saying, implicitly, that the past was better - 'Those were the days.' But that may not be the best way for most people to nostalgize. The comparison will not benefit, say, the elderly in a nursing home who don't see their future as bright. But if they focus on the past in an existential way - 'What has my life meant?' - then they can potentially benefit."

Three Times A Week, Tops

The only group of people whom Sedikides recommends not nostalgize are those who fear intimate relationships. Nostalgia hinges on reliving the joyous or grief-stricken, elated or morose memories we have with one another. Those who have difficulty reconnecting with those intense emotions may find nostalgia overwhelming.

For those who enjoy indulging in fanciful departures to the past, Sedikides says striking a healthy balance between overdoing it and non-confrontation is easy.

"If you're not neurotic or avoidant, I think you'll benefit by nostalgizing two or maybe three times a week," he said. "Experience it as a prized possession. When Humphrey Bogart says, 'We'll always have Paris,' that's nostalgia for you. We have it, and nobody can take it away from us. It's our diamond."

Source: Wildschut T, Sedikides C, Arndt J, Routledge C. Nostalgia: Content, Triggers, Function. Journal of Personality and Social Psychology. 2006.