STATEMENT OF PURPOSE
Sec. 636. [42 U.S.C. 9831]
It is the purpose of this subchapter to promote the school readiness of low-income children by enhancing their cognitive, social, and emotional development
(1) in a learning environment that supports childrens growth in language, literacy, mathematics, science, social and emotional functioning, creative arts, physical skills, and approaches to learning; and
(2) through the provision to low-income children and their families of health, educational, nutritional, social, and other services that are determined, based on family needs assessments, to be necessary.
I guess it's a leap of faith but if Head Start had been successful, then children living in poverty would benefit from education and be able to rise out of the poverty.
Implicit in my conjecture is a belief that education is a road from poverty to Good Times.
On the other hand, the Minnesota Twin Family Study suggests what a child becomes is strongly influenced by genetics and not the environment in which raised.
https://mctfr.psych.umn.edu/ and papers written on the results of the study.