We Now Know, How Animals Got Their Magnetic Sense (Animals / Biology)

The identity of a magnetic sensor in animals remains enigmatic. Although the use of the geomagnetic field for orientation and navigation in animals across a broad taxonomic range has been well established over the past five decades, the identity of the magnetic-sensing organ and its structure and/or apparatus within such animals remains elusive—‘a sense without a receptor’. Recently, Vortman and colleagues proposed that symbiotic magnetotactic bacteria (MTB) may serve as the underlying mechanism behind a magnetic sense in animals—‘the symbiotic magnetic-sensing hypothesis’.

Magnetotactic bacteria are a special type of bacteria whose movement is influenced by magnetic fields, including the Earth’s.

Animals that sense Earth’s magnetic field include sea turtles, birds, fish and lobsters. Sea turtles, for example, can use the ability for navigation to return to the beach where they were born.

Learning how organisms interact with magnetic fields can improve humans’ understanding of how to use Earth’s magnetic fields for their own navigation purposes. It can also inform ecological research into the effects of human modifications of the magnetic environment, such as constructing power lines, on biodiversity. Research into the interaction of animals with magnetic fields can also aid the development of therapies that use magnetism for drug delivery.

In the article, the researchers review the arguments for and against the hypothesis, present evidence published in support that has arisen in the past few years, as well as offer new supportive evidence of their own.

Their new evidence comes from Fitak, who mined one of the largest genetic databases of microbes, known as the Metagenomic Rapid Annotations using Subsystems Technology database, for the presence of magnetotactic bacteria that had been found in animal samples.

Previous microbial diversity studies have often focused on large patterns of the presence or absence of bacteria phyla in animals rather than specific species.

Fitak found, for the first time, that magnetotactic bacteria are associated with many animals, including a penguin species, loggerhead sea turtles, bats and Atlantic right whales.

For instance, Candidatus Magnetobacterium bavaricum regularly occurred in penguins and loggerhead sea turtles, while Magnetospirillum and Magnetococcus regularly occurred in the mammal species brown bats and Atlantic right whales.

According to Fitak, researchers still don’t know where in the animal that the magnetotactic bacteria would live, but it could be that they would be associated with nervous tissue, like the eye or brain.

Before joining UCF in 2019, Fitak worked for more than four years as a postdoctoral researcher at Duke University performing experiments to identify genes related to a magnetic sense in fish and lobsters using modern genomic techniques.

The hypothesis that animals use magnetic bacteria in a symbiotic way to gain a magnetic sense warrants further exploration but still needs more evidence before anything conclusive can be stated.

References: Eviatar Natan et al, Symbiotic magnetic sensing: raising evidence and beyond, Philosophical Transactions of the Royal Society B: Biological Sciences (2020). DOI: 10.1098/rstb.2019.0595 link: https://royalsocietypublishing.org/doi/10.1098/rstb.2019.0595

Scientists Found Hints Of Life On Venus (Planetary Science)

Measurements of trace gases in planetary atmospheres help us explore chemical conditions different to those on Earth. Our nearest neighbour, Venus, has cloud decks that are temperate but hyperacidic. Now, an international team of astronomers, led by Professor Jane Greaves of Cardiff University, reported the apparent presence of phosphine (PH3) gas in Venus’s atmosphere, where any phosphorus should be in oxidized forms.

Artist’s impression of Venus, with an inset showing a representation of the phosphine molecules detected in the high cloud decks. Credit: ESO / M. Kornmesser / L. Calçada & NASA / JPL / Caltech

The detection of phosphine molecules, which consist of hydrogen and phosphorus, could point to this extra-terrestrial ‘aerial’ life. The team first used the James Clerk Maxwell Telescope (JCMT) in Hawaii to detect the phosphine, and were then awarded time to follow up their discovery with 45 telescopes of the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile. Both facilities observed Venus at a wavelength of about 1 millimeter, much longer than the human eye can see—only telescopes at high altitude can detect this wavelength effectively.

Naturally cautious about the initial findings, Greaves and her team were delighted to get three hours of time with the more sensitive ALMA observatory. Bad weather added a frustrating delay, but after six months of data processing, the discovery was confirmed.

Synthesized false colour image of Venus, using 283-nm and 365-nm band images taken by the Venus Ultraviolet Imager (UVI). Credit: JAXA / ISAS / Akatsuki Project Team

Professor Hideo Sagawa of Kyoto Sangyo University then used his models for the Venusian atmosphere to interpret the data, finding that phosphine is present but scarce—only about twenty molecules in every billion.

The astronomers then ran calculations to see if the phosphine could come from natural processes on Venus. They caution that some information is lacking—in fact, the only other study of phosphorus on Venus came from one lander experiment, carried by the Soviet Vega 2 mission in 1985.

Massachusetts Institute of Technology scientist Dr. William Bains led the work on assessing natural ways to make phosphine. Some ideas included sunlight, minerals blown upwards from the surface, volcanoes, or lightning, but none of these could make anywhere near enough of it. Natural sources were found to make at most one ten thousandth of the amount of phosphine that the telescopes saw.

To create the observed quantity of phosphine on Venus, terrestrial organisms would only need to work at about 10% of their maximum productivity, according to calculations by Dr. Paul Rimmer of Cambridge University. Any microbes on Venus will likely be very different to their Earth cousins though, to survive in hyper-acidic conditions.

Earth bacteria can absorb phosphate minerals, add hydrogen, and ultimately expel phosphine gas. It costs them energy to do this, so why they do it is not clear. The phosphine could be just a waste product, but other scientists have suggested purposes like warding off rival bacteria.

Another MIT team-member, Dr. Clara Sousa Silva, was also thinking about searching for phosphine as a ‘biosignature’ gas of non-oxygen-using life on planets around other stars, because normal chemistry makes so little of it.

Other possible biosignatures in the Solar System may exist, like methane on Mars and water venting from the icy moons Europa and Enceladus. On Venus, it has been suggested that dark streaks where ultraviolet light is absorbed could come from colonies of microbes. The Akatsuki spacecraft, launched by the Japanese space agency JAXA, is currently mapping these dark streaks to understand more about this ‘unknown ultraviolet absorber.’

The team believes their discovery is significant because they can rule out many alternative ways to make phosphine, but they acknowledge that confirming the presence of “life” needs a lot more work. Although the high clouds of Venus have temperatures up to a pleasant 30 degrees centigrade, they are incredibly acidic—around 90% sulphuric acid—posing major issues for microbes to survive there. Professor Sara Seager and Dr. Janusz Petkowski, also both at MIT, are investigating how microbes could shield themselves inside droplets.

The team are now eagerly awaiting more telescope time, for example to establish whether the phosphine is in a relatively temperate part of the clouds, and to look for other gases associated with life. New space missions could also travel to our neighboring planet, and sample the clouds in situ to further search for signs of life.

References: Greaves, J.S., Richards, A.M.S., Bains, W. et al. Phosphine gas in the cloud decks of Venus. Nat Astron (2020). https://doi.org/10.1038/s41550-020-1174-4 link: https://www.nature.com/articles/s41550-020-1174-4

Studying For Test? Here’s Why You Shouldn’t Pull An All-Nighter (Biology)

Anyone who’s done with school doesn’t miss final exams. Or term papers. At least, they don’t miss the flurry of activity that leads up to them — living at the library all day long, writing and studying relentlessly, surviving on a diet of coffee and pizza. And, of course, pulling all-nighters. There’s nothing like ’em to get that paper done in time or cram those last few facts before a test. Well, it turns out that putting off sleep to study might hurt your grades after all. Here’s why pulling an all-nighter should be your last strategy for getting things done.

The most likely time for a college student to pull an all-nighter is right before an exam. Which is ironic, since science says that’s basically the worst possible time. According to Professor David Earnest from Texas A&M University, “Sleep deprivation’s effect on working memory is staggering. Your brain loses efficiency with each hour of sleep deprivation.” Plus, the middle of the night just isn’t the right time to start cramming. Just like the rest of your body, your brain works on an internal clock, and it just doesn’t retain information as well in the middle of the night as it does during the day. So if you’re staring into your textbooks in the wee hours of the morning, you’re working against your body’s natural processes.

But it’s not just that studying late means you’re not getting the most out of your brain. Missing sleep has a well-documented negative effect on academic performance. In one study encompassing more than 53,000 students, sleep problems increased the probability of dropping a course by 10 percent and lowered the average GPA by about 0.2 points. That’s comparable to the effects of regular binge drinking and excessive marijuana use. Furthermore, a Swiss study found that even one night without rest could have a lasting effect on your circadian rhythm. That’s right — it might take just one all-nighter to damage your sleep habits for the long term.

Fortunately, there are some people working to help college students overcome their sleep-deprived habits. The Center for College Sleep at the University of St. Thomas in St. Paul, Minnesota has proven how powerful shifting attitudes towards sleep can be. Thanks to the research done by the center, the school has begun enacting several measures to improve sleep habits among students. For example, many of the so-called “late night” events on campus have been moved to earlier in the evening. But it’s not just their own school’s ZZZs that they’re hoping to improve. Their College Sleep Questionnaire helps you assess your own sleep patterns and get the tools you need to improve your pillow time.

If you absolutely have to pull an all-nighter, do it smartly. Don’t do it to cram for a test the next day — you’ll only wreck your brain when you need it most. And once you’ve done it, wait a while before you do it again, since that lack of sleep adds up over time. Hold off on coffee until you’re deep in the process since you don’t want the caffeine crash to hit you mid-essay, and avoid other crash-inducing foods like sugary candy and high-carb pasta. Protein and fruit are a great alternative — try apples and peanut butter with your 2 a.m. cup of joe. If you can, try and schedule a short nap just to keep you going. 20 minutes can make a big difference. Oh, and the most important thing? When the morning comes and the paper’s been submitted, GET SOME SLEEP.

The “Bicameral Mind” Theory Says The Ancient Greeks Lacked Consciousness (Philosophy /Psychology / Neuroscience)

There is a lot of fuzziness around the idea of consciousness. How would you even begin to describe it? Everything that you experience is steeped in it, so you can’t quite put language to it. Who knows? Maybe it doesn’t even exist. Or maybe it does exist, but it was only invented in the last 3,000 years or so. Meet Julian Jaynes and his idea of the bicameral mind.

Think about consciousness for long enough, and you’ll drive yourself to distraction. To psychologist Julian Jaynes, the question of consciousness was big enough to last a lifetime. But unlike philosophers promoting panpsychism or other answers for the hard problem of consciousness, Jaynes was never particularly concerned with the mechanics of how consciousness arises from non-conscious physical material. In some ways, the question that drove him was even bigger: What is consciousness, and how does human consciousness differ from that of other living things?

His answer? Consciousness is much smaller, much rarer, and much younger than we tend to think. Forget about wondering if a dog, cat, or earthworm has consciousness — Jaynes hypothesized that even the ancient Greeks failed to achieve it. “Now, hold on,” you might be saying. “Ancient Greeks wrote some of the most enduring literature of all time — ‘The Iliad’ and ‘The Odyssey’ were written by non-conscious creatures?” To which Jaynes would reply, “Of course not. A conscious mind wrote The Odyssey.” An analysis of these two texts inspired the foundation of Jaynes’ metaphysical beliefs — the bicameral mind.

The bicameral mind (which may sound familiar to “Westworld” fans) is essentially a consciousness split in half. One half takes care of execution: When it receives the message that the body is hungry, it seeks and consumes food; when it gets the message that it has been wronged and insulted, it seeks vengeance. The other half is the one that sends those messages. Back before we had developed any sort of introspection, those messages would have hit the brain like the word of the gods. After all, where else could it have come from? The breakdown of the bicameral mind happens when that executive half starts really asking that question and finding the answer is “nowhere.” In other words, Jaynes says, consciousness didn’t arise until we stopped attributing our inner monologue to the gods.

So how do the Iliad and the Odyssey fit into this? Simple. The Iliad was “written” (really, passed on orally) long before the bicameral mind began examining itself. The Odyssey, its sequel, reflects that growth. In the Iliad, says Jaynes, the reader sees the protagonists defined by their inactivity — until a god comes in to tell them what to do. They seem to lack motivations and need an outside force to spur them to action. By contrast, the characters of the Odyssey make their own decisions for their own reasons. Nobody told Odysseus that he had to listen to the sirens singing — he lashed himself to the mast out of pure curiosity.

There’s another difference between the books that Jaynes called attention to — word choice. In the Iliad, many words we today associate with consciousness are used in a very different way. The Greek word psyche, which would later come to mean “soul” or “conscious mind,” was used in the Iliad to signify more concrete things: the air in one’s lungs, for example, or the blood in one’s veins. Thumos, which later would mean something like “emotional center,” seems to refer only to the quality of being in motion, and it’s something that might be granted by a god like Apollo. In other words, it’s almost as if people back then saw themselves as merely physical vessels for the will of the gods. True consciousness didn’t arise until we began to take credit for our own thoughts and motivations.

Here’s the thing about bicameralism. As popular as it was (and believe it or not, Jaynes’ book “The Origins of Consciousness in the Breakdown of the Bicameral Mind” was wildly popular with the 1970s public), the idea has a lot of major flaws. While many philosophers before and since Jaynes have embraced the idea that there is a sort of “focused” consciousness and a “background” consciousness (the one that takes action and the one that informs that action, in Jaynes’ model), his concept of consciousness as a cultural development instead of a biological one doesn’t jibe with most modern beliefs about neuroscience and psychology.

There’s also the simple fact that it seems to set up a hierarchy of consciousness that puts people who believe that divine forces influence their life towards the bottom and people with more atheistic beliefs in the “more conscious” space above them. It could even be read in much more harmful ways, positioning even some modern societies into a lesser realm of consciousness. And it’s not at all difficult to imagine the kinds of racist beliefs that could be propagated in such a hierarchical conception of consciousness. Still, even Daniel Dennett — the “no such thing as consciousness” guy — finds something pretty kind to say (along with a boulder-sized grain of salt). “There were a lot of really good ideas lurking among the completely wild junk,” he told Nautilus. That’s a fair point — but sometimes, the completely wild junk is where all of the fun stuff is.

For An All-Natural Painkiller, Try Holding Your Partner’s Hand (Psychology)

Human touch is important. Massages help us relax, hugs comfort us, and it feels like almost every pop song is called “Touch My Body” or something. New research shows just how important touch can be. When you’re in pain, holding hands with your romantic partner makes the discomfort less intense.

In a recent study, researchers studied 22 straight couples placed in various situations for two-minute intervals. Sometimes they were holding hands; sometimes they were in the same room, but not touching; and sometimes they were in adjacent rooms. There was also a pain dimension: In some situations, the woman in the couple had heat applied to her forearm, designed to produce a 60 on a pain scale of 0 to 100.

The researchers chose the woman as the unchanging “pain target” because previous research showed they elicit more empathy. It also echoed a typical birth scene, which was fitting since the entire study started in a delivery room. Lead author Pablo Goldstein had the idea for it while his wife was giving birth to their daughter.

“My wife was in pain, and all I could think was, ‘What can I do to help her?’ I reached for her hand and it seemed to help,” he said in a statement. “I wanted to test it out in the lab: Can one really decrease pain with touch, and if so, how?”

He and his co-authors thought there could be a link between pain and “interpersonal synchronization,” a physical phenomenon where we unconsciously sync our heartbeats, breathing, and brain activity with another person’s. You also might notice that when you’re walking with a friend, your footsteps sync up — that’s interpersonal synchronization, too. To test their hypothesis, the researchers tracked both partners’ heartbeat, breath, and brainwaves through each situation.

They found that synchronization on all metrics was highest when the two partners were holding hands and the woman was in pain, and furthermore, that holding hands with her partner reduced the woman’s discomfort. Instead of the man “feeling her pain,” as the cliché goes, she felt and absorbed his lack of pain.

We wouldn’t throw out your painkillers yet, but these results definitely suggest there’s a physiological reason we hold hands, especially with people who are suffering. They also suggest that partners can be of real service during the birth process.

What remains unclear is how this all works. The authors think couples might be synchronized at some baseline level whenever they’re together. Pain disrupts that status quo, though. In the study, syncing between not-touching couples who were in the same room dropped off when the woman felt pain. That could be because pain turns your attention inward, towards your own suffering. Holding hands — or perhaps any physical touch — seemed to revive and intensify that baseline synchronization.

That heightened synchronization could be a pain reliever, but it could also be a symptom of pain relief or just a random thing that correlates with pain relief. The two factors also correlate with a third factor — the man’s level of empathy for the woman, assessed via questionnaire. More empathetic men experienced higher synchronization when the woman was in pain, and that resulted in further pain reduction for her. It will take more research to hash out how and why all this works, but a sense of simultaneous emotional and physical connection sure seems to be a heck of a drug.

Waking Up On The Wrong Side Of The Bed Is Totally Real (Neuroscience)

You know that feeling when you get up and you’re already in a bad mood? You just know that traffic is going to be awful, that your boss is going to give you a hassle, that all of your meetings are going to drag on way past their end times. And then — great news! None of that actually happens. So why are you still so grouchy?

In a new study led by Jinshil Hyun, researchers found that a person’s mood upon waking up in the morning made a major impact on the rest of their day. You see, human beings have a terrific ability to predict what’s going happen over the course of the day, and that can be pretty useful when it comes to preparing for the worst. That might not be too surprising. The problem, said Hyun, is that ability to predict the worst “can also be harmful to your daily memory function, independent of whether the stressful events actually happen or not.”

That’s the real kicker. Sure, if you correctly intuit a bad day coming, you can get ready for it and make it easier on yourself. But if you incorrectly think a bad day is coming, your day is likely to go badly just because of that thought. That’s what the researchers suspected, anyway, and they tested that hypothesis by recruiting 240 people to check in on an app every morning to report their mood. Specifically, they had to predict how stressful they expected their day to be, and then report five more times throughout the day on their current stress levels. Finally, before heading to bed at the end of the night, they had to report how stressful they thought the next day would be.

There was one other requirement the researchers asked of the participants. Throughout the day, they had to perform small tests of their working memory. And, surprise surprise, higher levels of stress correlated with poorer performance. What really stood out, though, was that anticipating stress in the early morning had an even greater effect on working memory than actual stress did. That’s right — if you wake up feeling like everything will go terribly, your brain doesn’t work as well throughout the day.

One factor that didn’t have much effect on working memory was anticipation of stress the night before. That’s something to take away for your future stress management: If you think that there might be something stressful in your near future, get ready for it the night before. That way, you get to wake up with a plan instead of anticipating a bad time over your morning coffee. According to research, it’ll help you sleep better, too.

You Can Enter The Altered State Of Consciousness By Staring Into Someone’s Eyes For 10 Minutes (Neuroscience)

It’s a weird feeling, but sometimes even the most mundane moments can strike you as foreign. Ever hear a word enough times that it stops making sense? Ever hear your voice on a recording and have a disgusted reaction? Apparently, staring into someone’s eyes is another common activity that can yield an incredibly freaky result.

Drugs, meditation, and near-death experiences have all been described as producing an out-of-body sensation (we only suggest trying one of those three, for the record). Staring into another person’s eyes, according to a 2015 study, might just be another. By asking volunteers to sit and stare into each other’s eyes for a long period of time, Italian psychologist Giovanni Caputo from the University of Urbino concluded that “eye-staring” is a real way to induce an altered state of consciousness, drug-free.

For the study, Caputo asked 20 young adults (mostly women) to stare into a stranger’s eyes for 10 straight minutes in a dimly lit room. The lucky control group was told to sit in a chair and stare at a blank white wall for 10 minutes, knowing only that the study they were participating in related to a “meditative experience with eyes open.” After the 10 minutes were up, the participants were asked to fill out two questionnaires, one about any sensory distortions or out-of-body feelings they may have experienced, and the other about what they perceived in their partner’s face (eye-staring group) or their own face (control).

The results? Pretty surprising. The eye-starers said they’d had “a compelling experience unlike anything they’d felt before.” That’s no overstatement, either. The eye-starers scored higher on every aspect of both questionnaires, suggesting there’s something profound about staring into someone else’s eyes. The eye-starers reported that colors seemed less intense, sounds seemed quieter or louder than expected, and time seemed to move more slowly than usual, and that they just felt spaced out in general. On the weirder side, 90 percent of the participants in this group said they’d seen some deformed facial traits, 75 percent said they’d seen a monster, 50 percent said they saw hints of their own face in their partner’s face, and 15 percent said they’d seen a relative’s face. Remember, there were no drugs involved — these volunteers were getting high on eyes.

It’s (probably) not that our brains can’t handle looking at eyeballs. This weird outcome is likely the result of something called neural adaptation: “the mechanism by which neurons decrease or stop their response to unchanging stimulation,” Scientific American explains. This weirdness happened previously in a 2010 study where people stared at themselves in the mirror for a length of time. However, the results weren’t as extreme as the eye-starers in the 2015 study. Maybe the eyes have it after all.

Keeping Employees Available 24/7 Harms Collaboration And Mental Health (Psychology)

Smartphones and internet connectivity allow employees to be “always on” these days. But should you expect your team to be reachable 24 hours a day, seven days a week? Not if you want them to stay healthy and collaborate at their best, insists a fascinating pair of recent studies.

The fact that it’s stressful to get a panicked email from your supervisor at 11 p.m. will come as a shock to absolutely no one. But the first of these studies shows that you don’t have to have a boss with boundary issues to be made anxious by an office with an always-on culture.

The research, led by Virginia Tech management professor William Becker, found that even just the expectation that employees be available 24/7 raises health-eroding stress levels for both workers and their families. That was true even if well-meaning bosses didn’t even send late-night emails or otherwise abuse the privilege. Just the worry that they might was enough to produce negative effects.

A workplace’s well-intentioned “flexible hours” policy, in other words, often just results in expectation and worry. And that can eat away at employee wellness. “The insidious impact of ‘always on’ organizational culture is often unaccounted for or disguised as a benefit — increased convenience, for example, or higher autonomy and control over work-life boundaries,” Becker commented.

The health effects make up a pretty strong bit of evidence against expecting your people to be available whenever and wherever. But even if you’re the sort of hard-driving boss who is unconvinced by arguments about fluffy non-essentials like health and work-life balance, there is a solid business case for firm boundaries on when employees should be expected to stay connected.

Another new Harvard study, for instance, looked at the performance of three-person teams tasked with solving thorny complex problems. Some groups worked in isolation, some talked intermittently, and a final bunch constantly chatted thanks to always-on tech. You might think that more connection would mean better collaboration, but that’s not what the research team found.

The groups that interacted often but still guarded some alone time for solitary reflection actually came up with the best and most innovative solutions. The researchers concluded that alternating periods of connection with periods of isolation was the most effective form of collaboration.

“As we replace those sorts of intermittent cycles with always-on technologies, we might be diminishing our capacity to solve problems well,” Harvard’s Ethan Bernstein warned.

Taken together these two studies show that simply having the expectation that your team will always be reachable — even if you don’t abuse the privilege — is bad both for employees’ personal stress levels and their ability to collaborate together to produce their best work. People need some protected time away from work demands, and if you’re the boss, it’s your job to give it to them.

How do you do that? It just takes a few simple steps. Actively communicate your expectations for when and how your team should be reachable (so they don’t assume the worst and stress all the time). If you have an idea in the middle of the weekend, write it up and use an email-scheduling tool so it lands in your employees’ inboxes first thing Monday morning. Finally, set a good example yourself by, say, not instantly responding to a non-urgent 12 a.m. Slack question. A few changes can go a long way towards making sure you get the benefits of always-on technology without these research-verified pitfalls.

The Scientific Reason Why Some People Love Horror Movies And Others Hate Them (Psychology)

It sometimes seems like there are two types of people: Those who love horror movies and those who can be found safely under a blanket during the scary parts. The reason why you fall into one camp versus the other is a matter of nature and nurture.

Whether it’s a lion chasing you on a real savannah or a movie monster chasing a film’s main character, the sense of fear you get comes from the same place in the brain: the amygdala. That’s an ancient region that’s responsible for emotion processing and, importantly, triggering the fight-or-flight response. That’s when the body releases chemical messengers like adrenaline, cortisol, and epinephrine that increase your heartbeat, elevate your blood pressure, and shallow your breathing.

It appears that, for some reason, certain people are just wired to have a higher tolerance for anxiety and fear, with fight-or-flight responses that calm faster than most. As a result, they may have a greater need to seek out intense experiences to get the same effect. These “sensation seekers” tend to be more open to or even seek out experiences that help them achieve that state — things like skydiving or spicy food.

That’s the “nature” part of the equation. But there’s plenty of “nurture” here, too. For example, there also may be differences between men and women when it comes to fear fandom, but they’re not necessarily biological. Research suggests that men enjoy scary movies more than women, which could be because they’re socialized to be fearless and tough.

“Men often like [scary films] as date movies because women are more likely to seek physical closeness when they’re scared, and men can show off their strength and bravery,” Joanne Cantor, a professor at the University of Wisconsin at Madison, told Psych Central.

Experiences during childhood can also heavily influence a person’s tolerance for terror. Trauma stemming from things like neglect, poverty, and substance abuse can all affect the amygdala, putting it in a sort of survival mode that leads it to become more sensitive over time.

On the other end of the spectrum, positive childhood experiences with fear teach the brain that it’s fun to be scared.

“I once had a client who shared with me that when they were young they used to watch scary movies alongside their mother, and this made them feel safe, and that sometimes they even laughed together at the scary scenes,” Kelley Hopkins-Alvarez, a licensed professional counselor, told Reader’s Digest. “They definitely had a sense of what was reality and what was fantasy.”

“If we start tying scary things to friends, family, it comes together in this full picture of ‘This is entertaining, this is a fun thing that we do,'” Margee Kerr, sociologist and author of “Scream: Chilling Adventures in the Science of Fear,” told The Cut.

Your experiences immediately after watching a scary movie can have an effect too. Your body stays in a state of arousal afterward, and arousal heightens emotions. If you continue having a great night with friends, those positive feelings will cement the experience as a good one in your mind and will make you want to do it again. But if you get into a car accident on the way home, for example, your mind will register the experience as a bad one and you’ll be more inclined to skip a scary flick the next time around. Those scary associations carry more weight and are harder to get out of your head than the pleasant ones, so they’re likely to have greater bearing on your future behavior.

It is possible to shift from horror hater to lover with controlled exposure to scary stuff. If you’re able to withstand 90 minutes of fear, you’ll feel more resilient, which can actually make you become more resilient — that is, you’ll be less scared the next time around.

Parents who want to train their kids to be horror buffs should proceed with caution though: Kids under 7 have a difficult time distinguishing real threats from make-believe, and the risk may be greater than the reward.

“Intense fright reactions are much easier to prevent than to undo,” Cantor says.

Horror movies will also hit home harder for both kids and adults when the threats in the movie seem particularly realistic. A teen who babysits may be extra freaked by a movie about a terrorized babysitter, for example.

If you’re the type to clamor for tickets to the latest slasher film, enjoy the Halloween season! As for the rest of us? Embrace your scaredy-cat status — it makes November that much more pleasant.