Fourteen Democratic members of Congress have introduced legislation to lower the voting age in the United States from 18 to 16. Their bill would repeal the 26th Amendment, which in 1971 established 18 as the minimum voting age nationwide, and replace it with a new 28th Amendment making 16-year-olds eligible to participate in all elections. Four of the measure’s 14 sponsors are from Massachusetts: Representatives Seth Moulton, Ayanna Pressley, Lori Trahan, and James McGovern. The others are from New York, Illinois, Michigan, and Oregon.

To change the Constitution requires overwhelming public and political backing. Any proposed amendment must be passed by a two-thirds majority in each house of Congress and then be approved by three-fourths of the state legislatures. That sweeping support existed the last time the voting age was lowered. In fact, as far back as 1953, the Gallup Poll found that public approval for giving 18-year-olds the vote had surged to 63 percent; President Dwight Eisenhower endorsed making the change in his 1954 State of the Union address. Most Americans accepted the argument that if young men between 18 and 21 were old enough to be drafted and sent to war, they were old enough to be entrusted with the vote. The 26th Amendment was approved by Congress on March 23, 1971, and within 3½ months had been confirmed by the necessary 38 states — the fastest ratification of a constitutional amendment in US history.

By contrast, there is little public support for extending the franchise to high school sophomores.

As a newly elected member of Congress in 2019, Pressley’s first legislative proposal was an amendment to lower the voting age for federal elections to 16. The Democratic-led House handily defeated the amendment, 126-305. According to a nationwide Hill-HarrisX poll released in May 2019, “75 percent of registered voters opposed allowing 17-year-olds to participate in elections [and] 84 percent opposed allowing 16-year-olds to vote.” That sentiment crosses party lines. Large majorities of Democratic, Republican, and independent respondents are against allowing teens younger than 18 to vote.

So it’s safe to say that the latest proposal isn’t going anywhere. Still, it’s important to understand why further lowering the voting age is a bad idea.

Those who back voting rights for 16- and 17-year-olds argue that since kids that age can work, pay taxes, and get a driver’s license, it isn’t right to exclude them from the voting booth. Here’s how Moulton put it in 2020:

“Americans put a lot of faith in 16-year-olds. We let them drive, hire them at our businesses, and make them pay taxes.” Moreover, he wrote, “we know that voting at an early age helps encourage civic habits for life.”

Pressley goes even further. In a 2021 statement, she contended that a 16- or 17-year-old was qualified to vote by virtue of the “wisdom and maturity” that comes from living in a time of unique “challenges,” “hardships,” and “threats.” Young people, said Pressley, are entitled “to have a say in our federal elections and the policies that impact their lives today and will shape the nation in their lifetime.”

Such flimsy contentions don’t stand up to scrutiny.

Americans don’t put a lot of faith in 16-year-olds. To be sure, some kids at that age have jobs — some even contribute to their family’s expenses. But the great majority of teens don’t work, and vanishingly few hold down full-time jobs. Rare is the 16- or 17-year-old who foots the bill for groceries, rent, or utilities.

Yes, kids that age can legally drive, and yes, teenagers pay some taxes. But no one younger than 18 (and in some cases, 21) may legally drink alcohol or buy tobacco or marijuana. They may not purchase firearms or ammunition. They may not get married or adopt a child. They may not enlist in the military, buy a lottery ticket, book a hotel room or an Airbnb stay, apply for a mortgage, rent an apartment, file a lawsuit, obtain a credit card, work in a bar, or make a will.

In almost every area of life, society has established 18 as the age of majority because, broadly speaking, that is the age of maturity. Or at least the age of the minimum level of maturity to be entrusted with important decisions. It is well established that adult and teen brains operate differently. The prefrontal cortex — the brain region that governs decision making, long-term thinking, and rational judgment — isn’t fully developed until the mid-20s. Behavior and reactions in teens are instead controlled by the amygdala, the more emotion-driven, impulsive, primitive section of the brain.

If Moulton, Pressley, and their colleagues want to make a serious claim that 16-year-olds are mature enough to cast a ballot, they need to show why the scientific consensus on teen immaturity is wrong. And to be consistent, they should also be lobbying to lower the minimum legal age of every other activity to 16.

As for the idea that “voting at an early age helps encourage civic habits for life,” that too is unsupported by evidence.

The same claim was made when the 26th Amendment was being adopted. Lowering the voting age to 18, Senator Ted Kennedy declared, will “bring American youth into the mainstream of our political process” and “we will gain a group of enthusiastic, sensitive, idealistic, and vigorous new voters.”

That didn’t happen. Newly enfranchised 18-to-20-year-olds promptly became the least engaged cohort of voters. In every election, the youngest voters invariably participate at a lower rate than any others. There was considerable hoopla about how “high” turnout was for younger voters in last November’s midterm elections, but the data actually confirmed the longstanding pattern: Only 27 percent of voters younger than 30 bothered to cast a ballot. (On the other hand, those were the voters most likely to vote for Democratic candidates. A cynic could be forgiven for wondering whether that’s why Democrats like Pressley and her cosponsors are so eager to lower the voting age still more.)

Weak turnout rates among younger voters shouldn’t be surprising. Interest in government and politics tends to rise as the concerns of adulthood rise. Americans who have full-time jobs, who have to pay a mortgage, who are raising a family, who file yearly tax returns, who wrestle with health care premiums are more likely to take an interest in how they are governed than those who don’t. For perfectly understandable reasons, teens are apt to worry more about school, social media, and relationships with other teens than with candidates, legislation, and public policy.

If we don’t trust 16-year-olds to serve on a jury or sign a contract, we certainly shouldn’t expect them to cast thoughtful votes for presidents, governors, and members of Congress. In the eyes of society, adulthood begins at 18. Voting should begin then too.