Short answers, pulled from the story.
Early childhood education (ECE) covers the teaching of children from birth through age eight, traditionally up to the equivalent of third grade. It includes both formal and informal instruction and is recognized as a critical period in child development.
The Perry Preschool Project, conducted in Ypsilanti, Michigan in the 1960s and followed up for more than fifty years, found long-term economic benefits including reduced criminal convictions for male participants, higher earnings in middle adulthood, improved health outcomes for both sexes, and better educational attainment for treated females. The study also documented positive spillover effects on the children and siblings of the original participants.
A 2020 study in the Journal of Political Economy found that every dollar spent on high-quality early childhood programs returns $7.3 over the long term. Harvard economists Nathaniel Hendren and Ben Sprung-Keyser found that the average Marginal Value of Public Funds for early childhood and child health programs exceeds 5, compared to 0.5 to 2 for programs targeting adults.
By age three, children from high socioeconomic backgrounds have on average three times the vocabulary of children from low socioeconomic backgrounds. Participation in early childhood education has been shown to reduce this gap, and has been linked to higher high school graduation rates, better standardized test performance, and lower rates of grade repetition and special education placement.
Maria Montessori identified four planes of development: the first plane (birth to age 6), in which children have an "absorbent mind" and develop physical independence; the second plane (ages 6-12), focused on intellectual independence and cosmic education; the third plane (ages 12-18), centered on emotional independence and self-identity; and the fourth plane (ages 18-24), which focuses on financial independence and establishing one's role in the world.
Lev Vygotsky's zone of proximal development describes the distance between what a child can already do independently and what the child is on the verge of learning with support. In early childhood education, a teacher or older companion provides guidance and then gradually withdraws support as the child's capability grows. Vygotsky's theory, which emerged in the 1930s, emphasizes that social and cultural experiences shape cognitive development.