7 Scientific Studies About How Animals React to Music

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iStock

Music is pretty universally enjoyed ... when it comes to people. Animals, on the other hand, have diverse reactions to tunes. For every Ronan the head-bopping sea lion, there are plenty of creatures that can't keep the beat. Here are seven scientific discoveries about how some animals react to music, either created by humans or themselves. 

1. DOGS IN KENNELS MIGHT BE LESS STRESSED WHILE LISTENING TO CLASSICAL MUSIC.

In a 2012 study [PDF] published in The Journal of Veterinary Behavior, researchers from Colorado State University monitored the behavior of 117 kenneled dogs, including their activity levels, vocalization, and body shaking. The researchers played a few different types of music to the dogs, including classical, heavy metal, and an altered type of classical music. They also observed the dogs' behavior when no music was playing at all. They found that the dogs slept the most while listening to all kinds of classical music, indicating that it helped them relax. The dogs had the opposite reaction to the metal music, which provoked increased body shaking—a sign of nervousness.

The researchers noted the similarities between dogs and people when it comes to classical music. “These results are consistent with human studies, which have suggested that music can reduce agitation, promote sleep, improve mood, and lower stress and anxiety,” they wrote. They also point out that heavy metal music has anxiety-inducing effects on some people as well.

2. CATS DON'T CARE ABOUT HUMAN MUSIC, BUT SCIENTISTS ARE ABLE TO CREATE MUSIC THAT THEY DO ENJOY. 

Cats either don't care for, or are pretty indifferent to, human music. Thankfully, Charles Snowdon, a psychologist at the University of Wisconsin-Madison, David Teie, a composer at the University of Maryland, and Megan Savage, formerly of the University of Wisconsin-Madison and now a Ph.D. student at SUNY-Binghamton, have developed music that contains frequencies and tempos similar to the ones cats use to communicate. We tested some of the songs on one of our editor's cats earlier this year; you can listen to samples of the songs here.

Snowdon and Savage went to 47 households with cats and played them music, including two classical songs and two songs developed for felines. When the researchers played the latter, the cat was more likely to move towards the speaker, or even rub up against it, according to their study, which was published in the journal Applied Animal Behavior Science earlier this year. Interestingly, young and old cats reacted to the cat songs the most positively. Middle-aged cats showed more indifference.

3. IT'S ALSO POSSIBLE TO MAKE MONKEY MUSIC.

Cats weren't the first animals Snowdon, Savage, and Teie made species-specific music for. In 2009, they developed songs that mirrored the pitch of monkey calls. For their study, which was published in the journal Biology Letters, the scientists played the music for tamarin monkeys. Songs that were inspired by the calming calls the animals make caused the monkeys to relax; they even ate more while listening to those songs. But when the researchers played music that contained sounds similar to ones the monkeys make when they’re expressing fear, the monkeys became agitated. (You can listen to the songs here.) The monkeys were mostly indifferent to human music—their behavior didn't noticeably change when they were listening to Nine Inch Nails, Tool, or Samuel Barber. But, interestingly, when they heard “Of Wolf and Man” by Metallica, they grew calmer.

4. COWS PRODUCE MORE MILK WHEN THEY'RE LISTENING TO RELAXING MUSIC. 

In 2001, researchers at the University of Leicester played various songs to 1000-strong herds of Friesian dairy cows. Over a period of nine weeks, the researchers alternated between fast music, slow music, and silence for 12 hours each day. They found that calming music—like R.E.M.'s "Everybody Hurts," Simon & Garfunkel's "Bridge Over Troubled Water," and Beethoven's "Pastoral Symphony"—actually resulted in the cows producing 3 percent more milk—0.73 liters per cow per day. One of the lead researchers, Dr. Adrian North, told the BBC, “Calming music can improve milk yield, probably because it reduces stress.” The cows were not so into “Space Cowboy” by Jamiroquai or “Size of a Cow” by Wonderstuff.

5. ELEPHANTS MIGHT BE BETTER AT PLAYING MUSIC THAN HUMANS ARE.

Elephants are already known for their ability to paint with their trunks, but it turns out that they might be musically inclined as well. (Just check out this viral video of elephants swaying their trunks to violin music!) In northern Thailand, a conservationist named Richard Lair put together the Thai Elephant Orchestra, in which 16 elephants play specially developed instruments like steel drums and even harmonicas. Neuroscientists who have studied the music of the Thai Elephant Orchestra have determined that the animals are able to keep a very stable tempo on a large drum—even more stable than a human can.

6. BIRD BRAINS REACT TO MUSIC IN A MANNER SIMILAR TO HUMAN BRAINS. 

Birds are probably the most well-known singers of the animal kingdom. A few years ago, researchers at Emory University set out to learn whether birds are actually making music, like humans do. To find out, they examined the brains of both male and female white-tailed sparrows as they listened to the sounds of male birds.

When humans listen to music, our amygdalae often light up in response. It turned out that female white-tailed sparrows had similar brain responses to the bird sounds. The part of their brain that’s similar to the amygdala lit up while listening to the male’s song. The male birds, on the other hand, had brain reactions similar to when humans listen to music they don’t like. Sarah Earp, the study's lead researcher, explained, “We found that the same neural reward system is activated in female birds in the breeding state that are listening to male birdsong, and in people listening to music that they like.”

7. FISH KNOW THE DIFFERENCE BETWEEN COMPOSERS.

In 2013, a study was published in the journal Behavioral Processes that revealed that goldfish could be trained to distinguish between composers. Researchers at Keio University used pieces of music by two composers in the study: Igor Stravinsky and Johann Sebastian Bach. The goal was to train the goldfish to gnaw on a ball filled with food when the correct composer’s music was playing. One group of fish got Stravinsky and a separate group got Bach. When the fish heard music, they went to gnaw on the ball and were rewarded with food. Once the fish were correlating a composer’s music with the reward, the researchers tried playing the other composer’s music. The goldfish didn’t gnaw on the ball at that point, indicating that they knew enough about the pitch and timbre of their composer to not associate the novel music with food.

All images courtesy of iStock

8 Ways Science Can Boost Your Halloween Fun

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iStock

Halloween is all about embracing the supernatural, but science shouldn't entirely fall by the wayside during the spookiest of holidays. Here are a few ways it can actually improve your holiday, from making trick-or-treating easier to fooling your brain into thinking you're eating tasty treats even though you're nibbling on candy cast-offs.

1. Slow the decomposition of your Halloween jack-o'-lantern.

A Halloween display of five jack-o-lanterns
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You don't have to be an expert gardener to keep your jack-o'-lantern looking fresh all Halloween season long. While scouting out pumpkins, pick hard, unblemished ones and steer clear of those with watery dark spots. These splotches indicate frost damage.

Hold off on carving until right before Halloween so your gourds won't rot—but if you can't resist, try squirting their exteriors with lemon juice after you're done slicing and dicing. The acid inhibits pumpkin enzymes, which react with oxygen and cause browning. A light misting of bleach solution will help keep fungus at bay. Some apply vegetable oil or Vaseline to prevent shriveling and drying. We experimented with various techniques in this video.

For extra TLC, you might even want to bring your jack-o'-lanterns in at night if temperatures dip; if you live in a hot and humid area, extend its life by placing it in the fridge overnight. Try using glow sticks or LED lights instead of flesh-singeing candles.

2. Use apps to plan a treat-or-treating route.

Three children in Halloween costumes trick-or-treating
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Thanks to technology, trick-or-treaters (and their hungry adult companions) can now scout out which neighbors are doling out the best candy and which are sticking with Tootsie Rolls, apples, and toothbrushes. Simply download the app for Nextdoor, the neighborhood-based social network, to check out an interactive "treat map" that lets users tag whether their home is handing out treats, and what that treat is.

Since safety is far more important than sugar, guardians should also consider adding a tracking app to their arsenal come Halloween, especially if their kid's venturing out alone. The Find My Family, Friends, Phone app gives the real-time locations of trick-or-treaters, provides alerts for when they turn home, and also comes with a "panic" button that provides emergency contact details when pressed.

3. Optimize your candy's flavor (even if it's SweeTarts).

Hard candies and gummies strewn across a table
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Not crazy about this year's Halloween loot? Fool yourself into thinking those black licorice pieces and peanut chews taste better than they actually do by eating them after you scarf down the chocolate and Sour Patch Kids. According to a 2012 study published in Psychological Science, being aware that these items of candy are your very last candies actually tricks the brain into appreciating them more (and thus thinking they're tastier than they really are).

Meanwhile, a 2013 study from the same journal found that creating a candy-eating ritual enhances flavor and overall satisfaction. Nibble the ridged edges off a Reese's peanut butter cup before tackling the creamy center, sort the M&Ms by color, and take your time unwrapping a chocolate bar.

4. Create a DIY fog machine with carbon.

Dry ice in a glass bowl
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Save money at Party City by creating your own fog machine at home. When dropped in water, dry ice—or frozen carbon dioxide—creates a gas that's a combination of carbon dioxide and water vapor, but looks like the fog you'd see rolling through a haunted graveyard [PDF].

5. Eat sort-of-heart-healthy Halloween candy.

A stack of dark chocolate chunks on a dark stone background
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Halloween candy isn't always bad for you. While shopping for this year's trick-or-treat bounty, steer clear of sugary confections and milk chocolate mini-bars. Opt for dark chocolate treats instead. Research suggests that our gut microbes ferment the antioxidants and fiber in cocoa, creating heart-healthy anti-inflammatory compounds. Plus, dark chocolate or cocoa also appears to help lower blood pressure for people with hypertension, decrease bad cholesterol, and stave off cardiovascular disease and diabetes, among other benefits.

6. Analyze data on Halloween candy trends and give the people what they want.

Lollipops
5second/iStock via Getty Images

Thanks to data science, you can make sure you're giving out the best treats on the block. Bulk candy retailer CandyStore.com combed through 10 years of data (2007 to 2016, with a particular focus on the months leading up to Halloween) to gauge America's top-selling sweets. They created an interactive map to display their results, which includes the top three most popular Halloween handouts in each state and Washington, D.C. Be prepared for plenty of stoop-side visitors and adorable photo ops.

7. Bake better Halloween treats with chemistry.

Frosted Halloween cookies shaped like ghosts and pumpkins
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Cooking is essentially chemistry—and depending on your technique, you can whip up chewy, fluffy, or decadent Halloween treats according to taste.

Folding chunks of chilled butter into your dough will give you thick, cake-like cookies, as will swapping baking soda for baking powder. When butter melts, its water converts into gas, which leaves lots of tiny holes. If the butter flecks in question are colder and larger, they'll leave bigger air pockets. As for the baking powder, it produces carbon dioxide gas both when it's mixed into the dough and when it's heated. For an extra boost in texture, you can also try adding more flour.

Prefer chewier cookies? Start out with melted butter in the dough, and stick with plain old baking soda.

And for extra-fragrant and flavorful baked goods, opt to use dark sugars—like molasses, honey, and brown sugar—because they're filled with glucose and fructose instead of plain old sucrose. As cookies bake, they undergo two processes: caramelization, in which the sugar crystals liquefy into a brown soup; and the Maillard reaction, a chemical reaction between the dough's proteins and amino acids (flour, egg, etc.) and the reducing sugars that causes tasty browning.

8. Take deep breaths to stay calm in haunted houses.

A brown-haired woman in a red polka dot blouse standing with a frightened expression next to a spider web.
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Halloween can be tough for people with anxiety or low thresholds for fear. While visiting a haunted house or watching a scary movie, remember to take deep breaths, which fends off the body's flight-or-fight response, and reframe your anxiety in your mind as "excitement." It's also a good idea to schedule spine-chilling activities after an activity that triggers feel-good endorphins—say, after a walk to check out your neighbors' awesome Halloween displays.

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]

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