Why is the Drinking Age 21?

iStock
iStock

In short, we ended up with a national minimum age of 21 because of the National Minimum Drinking Age Act of 1984. This law basically told states that they had to enact a minimum drinking age of 21 or lose up to 10 percent of their federal highway funding. Since that's some serious coin, the states fell into line fairly quickly. Interestingly, this law doesn't prohibit drinking per se; it merely cajoles states to outlaw purchase and public possession by people under 21. Exceptions include possession (and presumably drinking) for religious practices, while in the company of parents, spouses, or guardians who are over 21, medical uses, and during the course of legal employment.

That answers the legal question of why the drinking age is 21, but what was the underlying logic of the original policy? Did lawmakers just pick 21 out of a hat because they wanted college seniors to learn the nuances of bar culture before graduation? Not quite. The concept that a person becomes a full adult at age 21 dates back centuries in English common law; 21 was the age at which a person could, among other things, vote and become a knight. Since a person was an official adult at age 21, it seemed to make sense that they could drink then, too.

WHO WAS RESPONSIBLE FOR LOWERING THE DRINKING AGE TO 18 FOR PART OF THE 20TH CENTURY, THOUGH?

Believe it or not, Franklin Roosevelt helped prompt the change in a rather circuitous fashion. FDR approved lowering the minimum age for the military draft from 21 to 18 during World War II. When the Vietnam-era draft rolled around, though, people were understandably a bit peeved that 18-year-old men were mature enough to fight, but not old enough to vote. Thus, in 1971 the states ratified the 26th Amendment, which lowered the voting age to 18. Legislators started applying the same logic to drinking. The drinking age, which the 21st Amendment made the responsibility of individual states, started dropping around the country.

Critics of the change decried rises in alcohol-related traffic fatalities among 18- to 20-year-old drivers in areas where the drinking age had been lowered. Indeed, one result of leaving states in charge of their own age was the creation of "blood borders" between states that allowed 18-year-olds to drink and those that didn't. Teenagers from the more restrictive state would drive into the one where they could buy booze, drink, and then drive home, which created a perfect storm for traffic fatalities. Even if teens weren't any more predisposed than older adults to drive after they'd been drinking, all of this state-hopping meant that those who did drive drunk had to drive greater distances to get home than their older brethren, who could just slip down the block for a beer or six. More miles logged in a car meant more opportunities for a drunken accident.

WHO LED THE BACK-TO-21 MOVEMENT?

Organizations like Mothers Against Drunk Driving began agitating for a uniform national drinking age of 21 to help eliminate these blood borders and keep alcohol out of the hands of supposedly less-mature 18-year-olds. As a result, President Reagan signed the aforementioned National Minimum Drinking Age Act of 1984. MADD's "Why 21?" website touts that, "More than 25,000 lives have been saved in the U.S. thanks to the 21 Minimum Legal Drinking Age." Traffic reports show a 61 percent decrease in alcohol-related fatalities among drivers under 21 between 1982 and 1998. Raw numbers show that drunk driving fatalities have definitely dropped since the early 1980s; since 1982, drunk driving fatalities have decreased 51 percent. Among drivers under 21, drunk driving-related deaths have decreased by 80 percent.

Teasing out the underlying cause of this reduction in total fatalities is no mean feat, though. Non-alcohol traffic fatalities have also declined relative to the number of miles driven over the same time period, which could be attributed to any number of causes, including increased seat belt usage, the widespread use of airbags, and other safety improvements to cars and roads. Moreover, drinking and driving for the whole population might be down as the result of increased education on its consequences, harsher penalties, improved enforcement, or increased stigmatization of drunk driving.

College presidents who supported the Amethyst Initiative—a movement launched in 2008 to reconsider the national drinking age of 21—admit that drunk driving is a serious problem, but they point out that it's not the only potential pitfall for young drinkers. They contend that by lowering the drinking age, colleges would be able to bring booze out into the open and educate students on responsible consumption. Such education might help curb alcohol poisoning, drunken injuries, drinking-fueled violence, and alcoholism on campuses.

Interesting bit of trivia: the group takes its name from the character Amethyst in Greek mythology. She ran afoul of a drunken Dionysus, who had her turned into white stone. When the god discovered what he'd done, he poured wine on the stone, turning it into the purple rock we know as amethyst. Ancient Greeks wore the mineral as a form of protection from drunkenness.

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.

If the Moon is Gradually Moving Farther Away From Us, Will Its Gravitational Pull Ever Cease on Earth?

iStock.com/kyoshino
iStock.com/kyoshino

Robert Frost:

The Moon is receding from the Earth, but will not continue to do so forever. We have to consider why the Moon is moving away at around 1.5 inches (3.78 cm) per year—a force is necessary to cause that.

The Moon exerts a tidal force on the Earth, causing a bulge. But, because the Earth rotates, that bulge is not directly between the Earth and Moon. It is slightly in front. That bulge has a gravitational pull on the Moon, causing it to move forward, slightly faster.

Causing the Moon to move slightly faster results in it climbing very slowly to a higher orbit. The Moon climbs higher by about 3.78 cm per year. But, since we just said that the force is gravitational and we know that gravity decreases with distance, we know that the force will also decrease with distance.

That means the rate at which the Moon recedes will decrease with time. But there's more to it than that. A force acts upon both bodies. While the impact on the Moon is causing it to recede, the impact on the Earth is that it is being caused to slow its rotation. The day is getting longer.

Eventually, the length of the day will match the orbital period of the Moon. That means both bodies will be tidally locked—meaning the same part of the Earth will always face the same part of the Moon. And if that happens, there is no longer a leading bulge and thus no longer a force causing the Moon to move away.

This would happen when the orbital period of the Moon is about 47 days. That would put the Moon at a distance of about 550,000 km; less than half as far again as it is today. In other words, not very far.

However, it will take a long time for that to happen. In the meantime, the Sun will turn into a red giant and its outer layers will extend to where Mars is today, meaning Earth, the Moon, and every In-N-Out restaurant will have been swallowed up and turned into loose atoms.

This post originally appeared on Quora. Click here to view.

What Makes Dogs Tilt Their Heads?

iStock.com/JoeChristensen
iStock.com/JoeChristensen

By tilting its head slightly to the side, a dog can melt the heart of even the most hardened cat person. Most everyone finds this behavior adorable, but few people can explain what compels a dog to do it. Are dogs somehow aware of the effect they have on humans, using a cute trick to exploit us for affection?

Experts say the real answer has more to do with your dog's ability to empathize. Dogs are impressively good at reading and responding to our body language and vocal cues. When you're lecturing your pooch for taking food off the counter, they're taking it all in even if the literal message gets lost in translation. Same goes for when you’re giving your pup praise. Dogs are capable of recognizing certain parts of human language, so when they cock their heads as you speak to them, it's possible they're listening for specific words and inflections they associate with fun activities like meals and playtime.

5186284546001

The head-tilt may also have something to do with how the canine ear is constructed. Even though dogs sense frequencies humans are incapable of hearing, their ability to detect the source of sounds is less precise than ours. A dog's brain calculates extremely minuscule differences between the time it takes a sound to reach each ear, so a simple change in head position could provide them with useful sensory information. When dogs tilt their heads, some experts believe they are adjusting their pinnae, or outer ears, in order to better pinpoint the location of a noise.

Stanley Coren of Psychology Today believes that vision also has something to do with this behavior. If you try holding your fist in front of your nose, you can get a fair sense of what it’s like to view the world with a muzzle. When watching someone speak, the "muzzle" will block the lower part of their face from view, and if you tilt your head to one side you will be able to see it more clearly. In addition to being able to perceive emotional cues in our voices, dog can also read our facial expressions. When cocking their heads to the side, Coren suggests that dogs are trying to get a better view of our mouths, where our most expressive facial cues originate.

If your dog is a frequent head-tilter, this could mean that they're especially empathetic. Some experts have reported that dogs who are more socially apprehensive are less likely to tilt their heads when spoken to. But if your dog doesn't display this behavior, there's no need to automatically label them as a canine sociopath (especially if they have pointy ears or a flatter snout). And even if the head tilt does come from instinct, the more owners respond to it with positive reinforcement, the more likely dogs are to do it in search of praise.

Have you got a Big Question you'd like us to answer? If so, send it to bigquestions@mentalfloss.com.

SECTIONS

arrow
LIVE SMARTER