The left’s pretensions to hold the moral high ground on fighting poverty face new skepticism. That’s one upshot, at least, of a new research finding that showering money on poor parents does nothing to help their children thrive. “The money did not make a difference,” a University of California economist, Greg Duncan, tells the Times. The research could go a way toward shaking liberals’ decades-long advocacy of welfare handouts.

“I was very surprised — we were all very surprised,” Mr. Duncan, a co-author of the working paper, titled “Baby’s First Years,” published by the National Bureau of Economic Research, says. It’s no wonder. Starting with the New Deal, and even more so since the Great Society, the left has held as an article of faith the idea that poverty can be fixed via more government spending. That contrasts with the conservative notion that work is the antidote to poverty.

Even FDR, who essentially forged the modern welfare state and its attendant bureaucratic leviathan, doubted the wisdom of cash welfare. “Continued dependence upon relief,” he told Congress in 1935, “induces a spiritual and moral disintegration fundamentally destructive to the national fiber.” He explained that “to dole out relief in this way is to administer a narcotic, a subtle destroyer of the human spirit.” His warning was ignored by later liberal lawmakers.

Feature, say, the new vogue on the left for the so-called Universal Basic Income. A Democratic presidential candidate, Andew Yang, is one of the proponents of that idea, which would set a minimum of $1,000 in earnings a month for all Americans, courtesy of the taxpayers. That idea has so far failed to prosper, though its logic was echoed by Covid stimulus handouts and even the new $1,000 gift to every newborn under the GOP’s so-called Trump Accounts.

Support for more generous welfare benefits is largely the province of the left. Feature, say, LBJ’s “so-called “War on Poverty,” in which he lavished billions in the hopes of lifting up the poor. The goal was, he said, “not only to relieve the symptom of poverty, but to cure it and, above all, to prevent it.” Some 60 years on, the poor are still with us. Liberals gripe that we didn’t spend enough. It’s more accurate to say that more money was not the answer.

That’s what makes the study by Mr. Duncan and his colleagues so compelling. They looked at the newborns of 1,000 “racially and ethnically diverse mothers” with low incomes. Some mothers were given $333 a month, and the rest got $20 a month. After four years, the study found “no statistically significant impacts of the cash transfers” on their children’s “language, executive function, social-emotional problems, and high-frequency brain activity.”

Nor, the researchers say, did the additional money help improve what researchers call “visual processing/spatial perception, pre-literacy,” or “maternal reports of developmental diagnoses.” One doesn’t want to derive too much significance from one study. Yet the findings proved significant enough for the Times to report that the study’s results “defied researchers’ predictions and could weaken the case for income guarantees.”

More broadly, the results confirm the common sense of Americans, going back to FDR, when it comes to the most effective way to fight poverty. Republicans have long touted the importance of bringing the poorest into the work force as a way to lift people out of poverty and into productive lives. This debate just roiled Congress after Democrats excoriated the GOP’s work requirements for the Medicaid health insurance program for the poor.

“You return the dignity of work to young men who need to be out working instead of playing video games all day,” Speaker Johnson argues. Congresswoman Alexandria Ocasio-Cortez denounces the move toward work requirements as a “disaster.” Yet the left’s welfare policies are the real catastrophe. The new research underscores the folly of encouraging dependence on government instead of promoting work to lift Americans out of poverty.