Why did we need yet another study proving the uselessness of Head Start? That Head Start accomplishes nothing, has been known for decades. Herrnstein & Murray covered the topic in The Bell Curve, Chapter 17:

Every serious attempt to assess the impact of Head Start on intelligence has found fade-out. Cognitive benefits that can often be picked up in the first grade of school are usually gone by the third grade. By sixth grade, they have vanished entirely in aggregate statistics. . . .
One response to the disappointment of Head Start has been to redefine its goals. Instead of raising intelligence, contemporary advocates say it reduces long-term school failure, crime, and illegitimacy and improves employability. These delayed benefits are called sleeper effects. . . . But even these claims do not survive scrutiny. The evidence for sleeper effects, such as it is, almost never comes from Head Start programs themselves but from more intensive and expensive preschool interventions.

That was published in 1994. The supporting academic references supplied by H & M go all the way back to 1969.

The Thernstroms covered the issue all over again nine years later in No Excuses. As noted in WAD, Chapter 6:

That landmark Great Society educational program, launched in 1965, is still going strong. The name of the program is still a sort of magic spell among liberals. Their faces light up with virtuous certitude as they utter it — Head Start! — and the effect of the spell, they seem to imagine, is to silence their opponent. You can’t POSSIBLY be against Head Start!
You should be. The Thernstroms reported that 20 million children had passed through it by 2003, at a cost to the federal taxpayer of $60 billion. They go on to report that while there is some slight, disputable evidence of marginal benefits for white children from Head Start, “It does not seem to have improved the educational achievement of African-American children in any substantial way.” Whether it has done anything for Hispanic children is not known.

A good strategy for reducing the number of discomfiting surprises in life, is to read the books that liberals denounce.

As to Maggie’s assertion that “These kids need help”: that sentiment is the germ of the welfarist mentality, which has inflicted far more damage on those kids than mere poverty ever could.