7 Scientific Studies About How Animals React to Music

iStock
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

5 Signs Humans Are Still Evolving

Lealisa Westerhoff, AFP/Getty Images
Lealisa Westerhoff, AFP/Getty Images

When we think of human evolution, our minds wander back to the millions of years it took natural selection to produce modern-day man. Recent research suggests that, despite modern technology and industrialization, humans continue to evolve. "It is a common misunderstanding that evolution took place a long time ago, and that to understand ourselves we must look back to the hunter-gatherer days of humans," Dr. Virpi Lummaa, a professor at the University of Turku, told Gizmodo.

But not only are we still evolving, we're doing so even faster than before. In the last 10,000 years, the pace of our evolution has sped up, creating more mutations in our genes, and more natural selections from those mutations. Here are some clues that show humans are continuing to evolve.

1. Humans drink milk.

Historically, the gene that regulated humans' ability to digest lactose shut down as we were weaned off our mothers' breast milk. But when we began domesticating cows, sheep, and goats, being able to drink milk became a nutritionally advantageous quality, and people with the genetic mutation that allowed them to digest lactose were better able to propagate their genes.

The gene was first identified in 2002 in a population of northern Europeans that lived between 6000 and 5000 years ago. The genetic mutation for digesting milk is now carried by more than 95 percent of northern European descendants. In addition, a 2006 study suggests this tolerance for lactose developed again, independently of the European population, 3000 years ago in East Africa.

2. We're losing our wisdom teeth.

Our ancestors had much bigger jaws than we do, which helped them chew a tough diet of roots, nuts, and leaves. And what meat they ate they tore apart with their teeth, all of which led to worn-down chompers that needed replacing. Enter the wisdom teeth: A third set of molars is believed to be the evolutionary answer to accommodate our ancestors' eating habits.

Today, we have utensils to cut our food. Our meals are softer and easier to chew, and our jaws are much smaller, which is why wisdom teeth are often impacted when they come in — there just isn't room for them. Unlike the appendix, wisdom teeth have become vestigial organs. One estimate says 35 percent of the population is born without wisdom teeth, and some say they may disappear altogether.

3. We're resisting infectious diseases.

In 2007, a group of researchers looking for signs of recent evolution identified 1800 genes that have only become prevalent in humans in the last 40,000 years, many of which are devoted to fighting infectious diseases like malaria. More than a dozen new genetic variants for fighting malaria are spreading rapidly among Africans. Another study found that natural selection has favored city-dwellers. Living in cities has produced a genetic variant that allows us to be more resistant to diseases like tuberculosis and leprosy. "This seems to be an elegant example of evolution in action," says Dr. Ian Barnes, an evolutionary biologist at London's Natural History Museum, said in 2010 statement. "It flags up the importance of a very recent aspect of our evolution as a species, the development of cities as a selective force."

4. Our brains are shrinking.

While we may like to believe our big brains make us smarter than the rest of the animal world, our brains have actually been shrinking over the last 30,000 years. The average volume of the human brain has decreased from 1500 cubic centimeters to 1350 cubic centimeters, which is an amount equivalent to the size of a tennis ball.

There are several different conclusions as to why this is: One group of researchers suspects our shrinking brains mean we are in fact getting dumber. Historically, brain size decreased as societies became larger and more complex, suggesting that the safety net of modern society negated the correlation between intelligence and survival. But another, more encouraging theory says our brains are shrinking not because we're getting dumber, but because smaller brains are more efficient. This theory suggests that, as they shrink, our brains are being rewired to work faster but take up less room. There's also a theory that smaller brains are an evolutionary advantage because they make us less aggressive beings, allowing us to work together to solve problems, rather than tear each other to shreds.

5. Some of us have blue eyes.

Originally, we all had brown eyes. But about 10,000 years ago, someone who lived near the Black Sea developed a genetic mutation that turned brown eyes blue. While the reason blue eyes have persisted remains a bit of a mystery, one theory is that they act as a sort of paternity test. “There is strong evolutionary pressure for a man not to invest his paternal resources in another man’s child,” Bruno Laeng, lead author of a 2006 study on the development of blue eyes, told The New York Times. Because it is virtually impossible for two blue-eyed mates to create a brown-eyed baby, our blue-eyed male ancestors may have sought out blue-eyed mates as a way of ensuring fidelity. This would partially explain why, in a recent study, blue-eyed men rated blue-eyed women as more attractive compared to brown-eyed women, whereas females and brown-eyed men expressed no preference.

Now Ear This: A New App Can Detect a Child's Ear Infection

iStock.com/Techin24
iStock.com/Techin24

Generally speaking, using an internet connection to diagnose a medical condition is rarely recommended. But technology is getting better at outpacing skepticism over handheld devices guiding decisions and suggesting treatment relating to health care. The most recent example is an app that promises to identify one of the key symptoms of ear infections in kids.

The Associated Press reports that researchers at the University of Washington are close to finalizing an app that would allow a parent to assess whether or not their child has an ear infection using their phone, some paper, and some soft noises. A small piece of paper is folded into a funnel shape and inserted into the ear canal to focus the app's sounds (which resemble bird chirps) toward the child’s ear. The app measures sound waves bouncing off the eardrum. If pus or fluid is present, the sound waves will be altered, indicating a possible infection. The parent would then receive a text from the app notifying them of the presence of buildup in the middle ear.

The University of Washington tested the efficacy of the app by evaluating roughly 50 patients scheduled to undergo ear surgery at Seattle Children’s Hospital. The app was able to identify fluid in patients' ears about 85 percent of the time. That’s roughly as well as traditional exams, which involve visual identification as well as specialized acoustic devices.

While the system looks promising, not all cases of fluid in the ear are the result of infections or require medical attention. Parents would need to evaluate other symptoms, such as fever, if they intend to use the app to decide whether or not to seek medical attention. It may prove most beneficial in children with persistent fluid accumulation, a condition that needs to be monitored over the course of months when deciding whether a drain tube needs to be placed. Checking for fluid at home would save both time and money compared to repeated visits to a physician.

The app does not yet have Food and Drug Administration (FDA) approval and there is no timetable for when it might be commercially available. If it passes muster, it would join a number of FDA-approved “smart” medical diagnostic tools, including the AliveKor CardiaBand for the Apple Watch, which conducts EKG monitoring for heart irregularities.

[h/t WGRZ]

SECTIONS

arrow
LIVE SMARTER