Retro Analysis: The Science of Nostalgia

JuliScalzi/iStock via Getty Images
JuliScalzi/iStock via Getty Images

Last August, the Fox television network took a cue from its 1990 programming line-up and debuted BH90210, a meta-throwback series starring the original cast of Beverly Hills, 90210 playing themselves in a revamp of the 1990-2000 teen soap hit. A Russian nesting doll of a show, the 90210 reboot appeared to be precision-engineered to stoke the nostalgic emotions of its fans, who were teens and young adults when it aired and were now primed for some comfort television. The premiere of BH90210 drew 6.1 million viewers, a record for an original summer series in 2019.

The 90210 reboot was just the latest attempt to monetize memory in popular culture. In 2019 alone, shows like Cobra Kai, Veronica Mars, Will and Grace, and The Conners have joined films like Rambo: Last Blood, Star Wars: The Rise of Skywalker, a live-action Lion King, and another Terminator in recalling stories and characters that first resonated 15 to 40 years before. Retrospective series like The Toys That Made Us take an exhaustive inventory of the plastic that populated store shelves in the 1980s and 1990s. Retro consoles like the NES Classic are gift-wrapped and doled out along with retro pop music compilations. One of the few non-sequel or remake movie hits of 2018 was Bohemian Rhapsody, an original film that nonetheless traded in on the cultural currency of Freddie Mercury, who died in 1991.

Nostalgia is so pervasive that it could practically introduce a unit of measurement—Jason Priestley leaning into a locker might provoke a five, while Ralph Macchio in a karate gi could be an eight. Entertainment seems primed to appeal to children—not actual kids facing adolescence, but those lurking inside the minds of adults. Increasingly, researchers are trying to better understand why nostalgia seems to be having a moment and how these exposures affect us neurologically. It turns out that dwelling on the past may be helping us to contextualize the present and prepare for the future.

 

Picture this: It’s late at night. You are out of college but have not yet embarked on a definitive career path. Bills are piled up on the table, a monument to adult responsibilities. Stress, anxiety, and student loans occupy your thoughts. On a social media page, you spot an advertisement for an old television show you liked. That brings you to YouTube, which has videos of Saturday morning cartoons you remember. For the next few hours, you drift from one clip to the next, happily regressing to a time when obligations were few and far between.

That’s nostalgia: a bittersweet longing or yearning for one's past. (Its counterpart, historical nostalgia, is having an affection for a different era, one you might not actually have lived through.) While that DuckTales episode might make you smile, it’s not so much the adventures of Scrooge McDuck and his nephews as the personal memories it conjures that bring you to a relaxed state.

“Having a nostalgic episode means you’re going to feel good, calm, at peace,” says Krystine Batcho, a professor of psychology at Le Moyne College in Syracuse, New York. “You stop feeling anxious. Your stress levels drop. You get a warm, soft, fuzzy feeling. Your brain is reviving old memories when you were a kid watching a show and smelling chocolate chip cookies baking in the kitchen.”

According to Batcho, this attraction to the past is somewhat paradoxical. We are a forward-looking and future-driven culture, obsessed with the latest technology. So why get hung up on history? It could be because we’re accelerating too quickly. Smart phones get more sophisticated every year. Things change so fast that returning to a static frame of mind offers comfort. “People want to go back to the feelings they had when they believed life was better,” Batcho tells Mental Floss. “It triggers associational memories. You remember aspects of life from back when you first watched a show.” A movie may be worse than you remember, but it remains tethered to a time when you enjoyed an uncomplicated state of mind and a life largely free of commitments.

That predictability is key. A memory can become distorted, and details could get muddled, but a happy recollection is going to be the same every time. Fundamentally positive memories are often stripped of negativity. “It’s comforting because you’re the master of that memory,” Batcho says. “You know your own lived-in past perfectly, but you have no idea what the future is going to be.”

When you view an old television show or movie or listen to favorite music, it’s often as a coping mechanism. The desire for nostalgia tends to spike during and proceeding transformative life events—a marriage, a job, a death—because it offers stability and a peaceful remembrance of a time when life was not so stressful. That’s why sources of nostalgia are identified with childhood and why it’s often 10 to 20 years before those pangs of memory kick in. By that time, you’ve experienced a milestone in your life that might compel you to look back.

A cassette tape is pictured
MarkPiovesan/iStock via Getty Images

“Nostalgia helps remind you who you are,” Batcho says. “It provides a comparison of yourself with yourself. Who were you back then? Who are you now? Watching something can trigger what you were thinking and feeling back then. Nostalgia allows us to monitor and keep track of our identities.”

 

Context and comfort make nostalgia a generally agreeable and positive emotion, but it wasn’t always thought of that way. In the 17th century, Swiss physician Johannes Hoffer defined nostalgia as a mental disorder, one suffered by Swiss soldiers dispatched to foreign territories who were homesick and dwelled on the details of their old lives. When it invites negative thoughts, then nostalgia can become bittersweet. More often, however, it’s literally rewarding.

Several years ago, Mauricio Delgado, researcher at Rutgers University who studies reward processing in the brain, returned to his former university to give an alumni talk. Walking the campus for the first time since graduating, Delgado found himself processing a flood of positive memories. He left feeling good about his visit, and he began to wonder what nostalgia would look like if it could be visualized neurologically.

“I thought there could be some reward value to this,” Delgado tells Mental Floss. “I wondered if it evoked similar processes in the brain.”

With his team, Delgado published a study in the journal Neuron in 2014 that provided some tangible and fascinating evidence of how we process fond recollections. After tasking his subjects with recalling positive life experiences—a vacation to Disney World, for example—Delgado observed their brains' activity through a functional magnetic resonance imaging (fMRI) scanner. The subject would hit a button when they began to recall the memory, then hit it again when they stopped. They would also summon memories they felt neutral about—grabbing groceries or shopping for shoes.

As they evoked a positive memory, the brains of his subjects lit up in a very specific way. “They tended to recruit brain systems involved in reward,” Delgado says. The brain’s processing of a reward happens in the striatum and prefrontal cortex, areas rich in dopamine receptors and active when people are enthusiastic about receiving good news or earning psychologically or tangibly positive assets like food or money. Nostalgia and those mental visits to the past offered neurochemical benefits not unlike a winning lotto ticket or receiving a “like” on Instagram.

In another study, Delgado had subjects exposed to stress, then recall a positive memory. The act of recollection dampened the cortisol response, leading to a stress-alleviating effect.

While these studies were not targeted to pop culture, one can glimpse the net result. Popular media is a conduit for pleasant memories, and pleasant memories produce positive neurological changes. “It’s reminiscing, and nostalgia is more like a television show from a past era,” Delgado says. “But nostalgia is what connects them.” In another fMRI study, some subjects passed on an opportunity for a financial reward for a neutral memory in order to continue drawing positive memories from the past. Making use of their internal time machine and the soothing state it offered was more valuable to them than money.

 

Nostalgia has been recognized by name since Hoffer’s time, but it seems as though the past several years have seen an popular emphasis on recalling content to provoke that reward response. The 1970s were not bountiful with reboots of I Love Lucy, Gunsmoke, or other material from the 1950s. What makes the 21st century unique in this regard? Why is a show's cancellation no longer a guarantee that it will never return?

Several vintage televisions are pictured
jakkapan21/iStock via Getty Images

According to David Gerber, a history professor emeritus at the University of Buffalo, we might be experiencing an uptick in nostalgia owing to the times we live in. “We’re passing through a period of very profound change,” Gerber says. “It’s not simply generational but global. There’s an industrial revolution from new information, electronic technology, and the globalization of markets. We’re passing through an era of profound concern for the planet.” Just as personal milestones can invoke personal nostalgia, political and environmental stresses can prompt collective nostalgia. We want to return to a simpler time and place because the one we currently occupy is one of upheaval.

Gerber also doesn’t discount the influence of mass media on our perceptions of time. “Media purposefully gives generations their own identities—Baby Boomers, Generation X," he says. These assigned categories make it easier to feel out of time when a new generation—like Millennials—comes along to remind an older population that their hairstyles, music, and fashion are no longer current, making them hyperconscious of the past they left behind.

Media makes it hard to forget: It’s easy to examine your feelings about Woodstock when hundreds of articles celebrating its 50th anniversary abound. With age encroaching, a desire to retrieve those memories grows. “It’s an emotional cushion for dealing with change,” Gerber says.

Nostalgia also relies heavily on social media, where collective recollections can be easily summoned by posting an old advertisement for a fondly remembered toy, game, or Starter jacket. “Now that more and more people don’t live near friends and relatives, it’s become a way to keep close to someone at a distance,” Batcho says. Nostalgia can also mend relationships, if one party has positive connotations with something that used to be shared as a couple. That Sopranos binge with an ex could stir feelings of forgotten emotion. “Nostalgic memories can remind you that you love a person,” she says.

While nostalgia often separates generations, it can also bring them closer together. “Part of what we see happening is that it allows for intergenerational connections,” Batcho says. She cites the fact that her adult son was in college and wondering which career path to pursue when he remembered how often his mother watched St. Elsewhere, the NBC television series set in a hospital that aired from 1982 to 1988. “He felt this kind of warm and fuzzy feeling about hospitals and realized it came from watching me watch the show,” Batcho says. “It’s like secondhand nostalgia.” Her son became a doctor—a decision he based in part on those memories.

 

Nostalgia often kicks in when enough time has passed to experience a major life event, which usually takes years from the time life consisted of cereal and Lunchables and when you need to think about a wedding. (Or a divorce.) But everyone’s relationship to the past is relative. Breaking Bad went off the air in 2013. In October, a follow-up film, El Camino, picks up where the series left off. Is that nostalgia? If you experienced a major milestone in the six years in between, maybe.

Batcho notes that nostalgia tends to drop off as we get older. In adulthood, we cope with the crises of the present by remembering the past. In middle age and into our third acts, we’re busy with an independent life, kids, and a career. Later, we realize there’s more time behind us than in front of us, and our perspective changes again. Nostalgia at this late stage can once again grow bittersweet. We recall a past we cannot reproduce.

There’s one further drawback to nostalgia. Like any pleasant stimulus, we can experience too much of it and become desensitized. After scoring record ratings for its debut, BH90210 kept dropping from week to week, eventually losing 60 percent of its viewers for its next-to-last episode. There seems to be a limited desire to check back in with Beverly Hills High.

“There is a saturation point,” Batcho says. “Once you satiate your need for nostalgia, it loses its value. Like a fine wine, it’s best enjoyed in appropriate amounts. It’s supposed to be a visit.”

Some Mathematicians Think the Equal Sign is On Its Way Out

Paperkites/iStock via Getty Images
Paperkites/iStock via Getty Images

A growing number of mathematicians are skeptical that the equal sign, traditionally used to show exact relationships between sets of objects, holds up to new mathematical models, WIRED reports.

To understand their arguments, it’s important to understand set theory—a theory of mathematics that’s been around since at least the 1870s [PDF]. Take the classic formula 1+1=2. Say you have four pieces of fruit—an apple, an orange, and two bananas—and you put the apple and the orange on one side of a table and the two bananas on the other. In set theory, that’s an equation: One piece of fruit plus one piece of fruit on the left side of the table equals two pieces of fruit on the right side of the table. The two sets, or collections of objects, are the same size, so they’re equal.

But here’s where it gets complicated. What if you put an apple and a banana on the left side of the table and an orange and a banana on the other side? That’s clearly different from the first scenario, but set theory writes it as the same thing: 1+1=2. What if you switched the order of the first set of objects, so instead of having an apple and an orange, you had an orange and an apple? What if you had only bananas? There are potentially infinite scenarios, but set theory is limited to expressing them all in only one way.

“The problem is, there are many ways to pair up,” Joseph Campbell, a mathematics professor at Duke University, told Quanta Magazine. “We’ve forgotten them when we say ‘equals.’”

A better alternative is the idea of equivalence, some mathematicians say [PDF]. Equality is a strict relationship, but equivalence comes in different forms. The two-bananas-on-each-side-of-the-table scenario is considered strong equivalence—all of the elements in both sets are the same. The scenario where you have an apple and an orange on one side and two bananas on the other? That’s a slightly weaker form of equivalence.

A new wave of mathematicians is turning to the idea of category theory [PDF], which is based in understanding the relationships between different objects. Category theory is better than set theory at dealing with equivalence, and it’s also more universally applicable to different branches of mathematics.

But a switch to category theory won’t come overnight, according to Quanta. Interpreting equations using equivalence rather than equality is much more complicated, and it requires relearning and rewriting everything about mathematics—even down to algebra and arithmetic.

“This complicates matters enormously, in a way that makes it seem impossible to work with this new version of mathematics we’re imagining,” mathematician David Ayala told Quanta.

Several mathematicians are at the forefront of category theory research, but the field is still relatively young. So while the equal sign isn’t passé just yet, it’s likely that an oncoming mathematical revolution will change its meaning.

[h/t Wired]

7 Facts About Blood

Moussa81/iStock via Getty Images
Moussa81/iStock via Getty Images

Everyone knows that when you get cut, you bleed—a result of the constant movement of blood through our bodies. But do you know all of the functions the circulatory system actually performs? Here are some surprising facts about human blood—and a few cringe-worthy theories that preceded the modern scientific understanding of this vital fluid.

1. Doctors still use bloodletting and leeches to treat diseases.

Ancient peoples knew the circulatory system was important to overall health. That may be one reason for bloodletting, the practice of cutting people to “cure” everything from cancer to infections to mental illness. For the better part of two millennia, it persisted as one of the most common medical procedures.

Hippocrates believed that illness was caused by an imbalance of four “humors”—blood, phlegm, black bile, and yellow bile. For centuries, doctors believed balance could be restored by removing excess blood, often by bloodletting or leeches. It didn’t always go so well. George Washington, for example, died soon after his physician treated a sore throat with bloodletting and a series of other agonizing procedures.

By the mid-19th century, bloodletting was on its way out, but it hasn’t completely disappeared. Bloodletting is an effective treatment for some rare conditions like hemochromatosis, a hereditary condition causing your body to absorb too much iron.

Leeches have also made a comeback in medicine. We now know that leech saliva contains substances with anti-inflammatory, antibiotic, and anesthetic properties. It also contains hirudin, an enzyme that prevents clotting. It lets more oxygenated blood into the wound, reducing swelling and helping to rebuild tiny blood vessels so that it can heal faster. That’s why leeches are still sometimes used in treating certain circulatory diseases, arthritis, and skin grafting, and helps reattach fingers and toes. (Contrary to popular belief, even the blood-sucking variety of leech is not all that interested in human blood.)

2. Scientists didn't understand how blood circulation worked until the 17th century.

William Harvey, an English physician, is generally credited with discovering and demonstrating the mechanics of circulation, though his work developed out of the cumulative body of research on the subject over centuries.

The prevailing theory in Harvey’s time was that the lungs, not the heart, moved blood through the body. In part by dissecting living animals and studying their still-beating hearts, Harvey was able to describe how the heart pumped blood through the body and how blood returned to the heart. He also showed how valves in veins helped control the flow of blood through the body. Harvey was ridiculed by many of his contemporaries, but his theories were ultimately vindicated.

3. Blood types were discovered in the early 20th century.

Austrian physician Karl Landsteiner discovered different blood groups in 1901, after he noticed that blood mixed from people with different types would clot. His subsequent research classified types A, B and O. (Later research identified an additional type, AB). Blood types are differentiated by the kinds of antigens—molecules that provoke an immune system reaction—that attach to red blood cells.

People with Type A blood have only A antigens attached to their red cells but have B antigens in their plasma. In those with Type B blood, the location of the antigens is reversed. Type O blood has neither A nor B antigens on red cells, but both are present in the plasma. And finally, Type AB has both A and B antigens on red cells but neither in plasma. But wait, there’s more! When a third antigen, called the Rh factor, is present, the blood type is classified as positive. When Rh factor is absent, the blood type is negative.

Scientists still don’t understand why humans have different blood types, but knowing yours is important: Some people have life-threatening reactions if they receive a blood type during a transfusion that doesn’t “mix” with their own. Before researchers developed reliable ways to detect blood types, that tended to turn out badly for people receiving an incompatible human (or animal!) blood transfusion.

4. Blood makes up about 8 percent of our total body weight.

Adult bodies contain about 5 liters (5.3 quarts) of blood. An exception is pregnant women, whose bodies can produce about 50 percent more blood to nourish a fetus.)

Plasma, the liquid portion of blood, accounts for about 3 liters. It carries red and white blood cells and platelets, which deliver oxygen to our cells, fight disease, and repair damaged vessels. These cells are joined by electrolytes, antibodies, vitamins, proteins, and other nutrients required to maintain all the other cells in the body.

5. A healthy red blood cell lasts for roughly 120 days.

Red blood cells contain an important protein called hemoglobin that delivers oxygen to all the other cells in our bodies. It also carries carbon dioxide from those cells back to the lungs.

Red blood cells are produced in bone marrow, but not everyone produces healthy ones. People with sickle cell anemia, a hereditary condition, develop malformed red blood cells that get stuck in blood vessels. These blood cells last about 10 to 20 days, which leads to a chronic shortage of red blood cells, often causing to pain, infection, and organ damage.

6. Blood might play a role in treating Alzheimer's disease.

In 2014, research led by Stanford University scientists found that injecting the plasma of young mice into older mice improved memory and learning. Their findings follow years of experiments in which scientists surgically joined the circulatory systems of old and young mice to test whether young blood could reverse signs of aging. Those results showed rejuvenating effects of a particular blood protein on the organs of older mice.

The Stanford team’s findings that young blood had positive effects on mouse memory and learning sparked intense interest in whether it could eventually lead to new treatments for Alzheimer’s disease and other age-related conditions.

7. The sight of blood can make people faint.

For 3 to 4 percent of people, squeamishness associated with blood, injury, or invasive medical procedures like injections rises to the level of a true phobia called blood injury injection phobia (BII). And most sufferers share a common reaction: fainting.

Most phobias cause an increase in heart rate and blood pressure, and often muscle tension, shakes, and sweating: part of the body’s sympathetic nervous system’s “fight or flight” response. But sufferers of BII experience an added symptom. After initially increasing, their blood pressure and heart rate will abruptly drop.

This reaction is caused by the vagus nerve, which works to keep a steady heart rate, among other things. But the vagus nerve sometimes overdoes it, pushing blood pressure and heart rate too low. (You may have experienced this phenomenon if you’ve ever felt faint while hungry, dehydrated, startled, or standing up too fast.) For people with BII, the vasovagal response can happen at the mere sight or suggestion of blood, needles, or bodily injury, making even a routine medical or dental checkup cause for dread and embarrassment.

SECTIONS

arrow
LIVE SMARTER