In the US, the movement for a lower voting age lost momentum about 10 years ago. Just one municipality lets 16-year-olds vote in local elections: Takoma Park, Maryland. The idea of lowering the voting age is more frequently argued in middle school debates than it is in serious policy discourse.
That's too bad. The evidence suggests it might be worth trying.
What Austria and Scotland learned from letting 16-year-olds vote
In 2007, Austria became the first established democracy to lower its voting age for national elections to 16. (People can also vote at 16 in Brazil and Malta, and in local or state-level elections in parts of Switzerland and Germany.)
A study of Austria's expanded electorate found that 16- and 17-year-olds were not less informed than 18-year-olds. Nor were they less willing to participate in politics. And they could pick candidates who represented their own political beliefs just as well as older voters. That addressed several of the common arguments against lowering the voting age: that 16- and 17-year-olds simply aren't ready to vote.
"Lowering the voting age does not appear to have a negative impact on input legitimacy and the quality of democratic decisions," three Austrian researchers wrote in the journal Electoral Studies. "This means that the potential positive consequences of this reform merit particular consideration and should also be empirically studied."
Another experiment with a lower voting age in an established democracy happened in Scotland earlier this year, where teenagers as young as 16 were allowed to vote in its historic independence referendum.
Scotland didn't run exit polls, so it's impossible to know how many of those 16- and 17-year-olds actually voted, how they voted, or whether their votes turned out to be decisive. But it's revived a campaign to lower the UK's voting age to 16, with political rivals from Scotland's Labour and Conservative Parties praising the energy and commitment of Scotland's teenagers during the referendum.
18 is an arbitrary age, too
When the voting age was lowered from 21 to 18, 18 had a special and unique symbolic resonance: it was when you could be drafted to serve in the armed forces and be injured or die in the Vietnam War. But military conscription ended two years after the voting age was lowered.
Age restrictions were never given the lengthy considerations given to property qualifications and restrictions based on citizenship — it was enough for men like John Adams to simply assume that civic competence grew naturally with age. In 1776, Adams delivered a hand-waving defense of Massachusetts' voting age in a letter to James Sullivan, who would later become the state's governor. "What Reason Should there be, for excluding a Man of Twenty years, Eleven Months and twenty-seven days old, from a Vote when you admit one, who is twenty one?" he wrote. "The Reason is, you must fix upon Some Period in Life, when the Understanding and Will of Men in general is fit to be trusted by the Public." Translation: "You've gotta pick some age, right?" One can almost picture him shrugging as he wrote those words.
Laurence Steinberg, a psychologist and expert in adolescence, agrees that 16-year-olds are just as capable as 18-year-olds. He distinguishes between "cold cognition" — decisions that you get to think about in advance, such as voting or consenting to a medical procedure — and "hot cognition," decisions made on the fly. Adolescents are impulsive, which makes their hot cognition skills iffy. But they're perfectly capable of cold cognition before they enter the voting booth, he writes in the Los Angeles Times.
Why a younger voting age should start at the state level
During the 1960s, the movement to lower the voting age from 21 to 18 started in four states. It then spread nationwide with a constitutional amendment passed in 1971. A handful of states seem like a natural place to experiment with setting the voting age even lower today.
State legislatures set many of the policies that most directly affect 16-year-olds' lives, from whether they're able to drive to how much state funding their schools get to what they'll eventually pay in college tuition. If we're going to experiment with giving older teenagers a voice in politics, it makes sense to start at the state level, where it could make the most difference in their day-to-day existence. For the same reason, allowing younger voters into local school board elections would be a logical step.
The biggest argument against a younger voting age is that teenagers won't take advantage of it. This could well be true. Voters under 30 are notoriously terrible about showing up to the polls. And despite supporters' arguments that starting voting at 16 will instill a lifelong love of voting, there's little evidence that a lower voting age will increase overall participation rates.
But that's also somewhat beside the point. When it comes to who's allowed to vote, it makes sense to err on the side of more democracy, not less. In lowering the voting age, the question shouldn't be "why" — it should be "why not?"