In an important recent Nature article, Friedman et al.1 modelled within-country inequalities in primary, secondary, and tertiary education and forecast progress towards education-related targets of the Sustainable Development Goals (SDGs). They found that most countries are on track to achieve near-universal primary education by 2030 and schooling gender gaps are closing, but parts of sub-Saharan Africa, North Africa and the Middle East still lag far behind. Progress in secondary education is less promising, with only 10% of adolescents in poorer countries completing 12 schooling grades. An Editorial on the paper (Education must fix its data deficit)2 notes that data on disparities have played substantial roles in driving gains achieved to date1. It calls for more data to identify which groups of children need most help, and urges further progress in tracking what children learn in addition to their completed schooling grades.
SDG 4’s goal is to ensure inclusive and equitable quality education and promote lifelong learning opportunities for all. Friedman et al.’s1 paper addresses two SDG 4 targets: 4.1 (free, equitable and quality primary and secondary education) and part of 4.3 (ensuring that men and women have equal access to affordable and quality tertiary education). However, their paper entirely overlooks Target 4.2, which states that by 2030, all girls and boys should have access to quality early childhood development, care and pre-primary education so that they are ready for primary education. As we enter the last decade of the SDG agenda, it is crucial that we hold the world accountable for achieving this target because it is foundational to all learning and the achievement of SDG 4 in totality. SDG 4.2 can only be achieved by collecting and analysing data to track progress and disparities in early-life education, and highlighting governmental actions to accelerate progress by addressing gaps.
The 1990 Jomtien World Declaration on Education for All3 stated that “Learning begins at birth”, and the importance of child development in preschool years has been included in all international declarations since, including the 2000 Dakar Framework for Action: Education for All4, the Millennium Development Goals and the SDGs. Given strong evidence that foundations for adolescent and adult human capital are established in the early years, we can no longer consider education to begin when children start primary school. It is critical to bear in mind the long-term importance of the enormous learning that occurs—or does not occur—from before birth to when children walk into their first-grade classrooms. Inequalities are evident from the start and generally very large by the time children enter formal schooling systems.
Promoting early learning outcomes and mitigating inequities requires tracking children’s progress or development from their very first years of life. SDG 4.2 indicators focus on the proportion of children aged 24–59 months who are developmentally on track in health, learning and psychosocial wellbeing, by sex (4.2.1) and participation rates in organized learning (1 year before the official primary entry age), by sex (4.2.2)5. The 2020 UN Secretary General’s Report6, based on 74 countries with comparable 2011–2019 data, states that ~70% of children 3–4 years of age are on track developmentally in at least three of the following domains: literacy-numeracy, physical development, social-emotional development and learning. Participation in organized learning programmes 1 year before the official age of primary school entry grew steadily from 62% in 2010 to 67% in 2018. Variation among countries remains wide7, with values ranging from 9% to nearly 100%. Of 16 countries with trend data since 2010, the largest progress was observed in Iraq, Laos and Sierra Leone, but no progress or even reduced coverage in Cameroon, Chad or Swaziland7. Further, large socioeconomic and rural-urban within-country disparities are found for preschool children8.
The importance of early childhood development at home, child day care and in pre-primary education
The evidence is incontrovertible: learning begins at and even before birth. Brain development is extremely rapid and learning takes place as children interact with adults who facilitate, name and interpret their experiences. Children’s brain volumes double during their first year and reach 80–90% of their adult sizes by age 39, and learning progresses rapidly across all modalities10,11. For example, foetuses and newborns distinguish their mothers’ voices from others12 and, within days after birth, associate auditory and visual information together, such as mothers’ voices with their faces13.
Not only are children actively learning about people and objects around them from birth, but they are learning how to learn, mainly from other people. Child-directed speech, emotional attunement between caregivers and children that promotes affection and trust, and predictable adult responsiveness to children’s communication are foundations of children’s learning14. The importance of these elements for young children’s development is articulated in the Nurturing Care Framework (NCF), developed in follow-up of the 2017 Lancet series Advancing Early Childhood Development: From Science to Scale15. The NCF describes the qualities of holistic environments that promote, support and protect young children’s health, nutrition, safety, and early learning, and satisfy the need for warm and affectionate responsiveness from others.
Clearly, the elements for success in school and lifelong learning are developed long before children enter primary schools. Both stimulating home environments and participation in high-quality early childcare and educational programmes independently and interactively support children’s early learning. One or more years of quality pre-primary education builds cognitive and social skills founded on the substantial learning that takes place through interactions with familiar adults and other children at home, as well as in child day care.
Poverty and undernutrition mar early development for far too many children, estimated at 250 million, or 43%, of all children under 5 years old in low- and middle-income countries (LMICs)16,17. These early disadvantages put children at risk of inadequate learning, incomplete schooling and lower adult earnings18,19,20. The average percentage losses of adult income resulting from loss of schooling due to stunting or living in extreme poverty in early life are estimated to be about 27%21. Early disadvantages are compounded by poor quality and high out-of-pocket costs of early childcare and educational and pre-primary programmes. Both poverty and stunting can be mitigated by governmental actions. For example, both minimum wage and parental leave policies have been shown to improve nutrition, family income, and healthy child development22,23.
Unequal opportunities from the start
Inequalities in learning and development are evident early. Analysis of data collected since 2010 through 135 nationally representative datasets (primarily Demographic Health Surveys & Multiple Indicator Cluster Surveys) showed that risks for early childhood development and opportunities for early learning varied widely across regions7. All four indicators analysed showed clear gradations of increasing disadvantage for young children from upper-middle- to lower-middle- to low-income countries. From 16% to 36% to 55% of children under age five were exposed to extreme poverty or stunting; 15% to 38% to 46% of 3- to 4-year-olds were not receiving basic stimulation for learning at home; 13% to 26% to 40% of 3- to 4-year-olds were not developmentally on track (as measured by the Early Childhood Development Index, or ECDI), and from 47% to 63% to 79% of children of the same age were not attending early childcare and educational programmes. Gradations of disadvantage were found also within countries with respect to household wealth and rural versus urban residence, with poor rural households having the greatest disadvantages. The differences between boys and girls on the four indicators were either small or non-significant, with slight advantages for girls on stunting and ECDI7. Consistent with the schooling data reported by Friedman et al.1, children in sub-Saharan Africa were most likely at risk due to poverty and stunting, had the lowest percentages receiving adequate stimulation at home (47% vs. 69% for the average of 62 countries from different regions), the smallest proportion developmentally on track in terms of the ECDI (61% vs. 75% for the overall average), and the lowest percentages attending some form of early care and educational programmes (24% vs. 39% for the overall average).
At least 95% of children between 4 years of age and entry into compulsory primary school participate in pre-primary programmes in the 28 European Union countries, reaching the target set in their Strategic Framework for Cooperation in Education and Training24. Pre-primary programme enrolments globally have increased dramatically from 35% in 2000 to over 62% in 2019, with increases in all regions. In LMICs, enrolments nearly doubled over this period. For example, enrolments increased from 9 to 20% in low-income countries and from 45 to 76% in upper-middle-income countries. However, substantial gaps remain, between and within countries and between urban and rural areas and by socioeconomic status. For example, the 2019 pre-primary programme gross enrolment rate was only 32% in sub-Saharan Africa25 compared to 62% globally.
Governments vary in their provision of pre-primary programmes. Among 194 countries, 68 countries have legal mandates for either free and/or compulsory pre-primary education. Among these 68 countries, pre-primary education is free and compulsory in 46 countries. Notably, legal provisions for free pre-primary education exist in 3/27 low-income countries, 11/34 lower-middle-income countries, 23/33 upper-middle-income countries, and 24/26 high-income countries. There is thus a gradient between income and legal provision for pre-primary education. On the one hand, countries that legislated either free and/or compulsory education saw their enrolments increase from 41.4% in 1999 to 82.8% in 2018. On the other hand, countries with no legal frameworks for pre-primary education increased from 52.9% in 1999 to 63% in 201826. Countries offering 1 year of tuition-free pre-primary programming, had 16% higher gross enrolment rates compared to countries without tuition-free pre-primary provision27. Countries providing at least 1 year of free and compulsory pre-primary programming had 10% higher primary school completion rates27, suggesting that free compulsory programmes can set children on paths to longer-term educational attainment.
Inequalities in both provision of and access to early learning opportunities accumulate and extend as children progress through pre-primary, primary and secondary schooling28. This lessens children’s chances of catching-up and of realizing the global community’s efforts to eliminate documented inequalities in schooling1.
Early disadvantage is costly
Learning occurs progressively and skills build on each other. Complementarities between skills increase motivation and make learning at later ages easier. A recent national longitudinal study showed dynamic complementarity between access to pre-primary education and improved primary and secondary education, with access to both particularly beneficial in terms of increased educational attainment and earnings for children from more disadvantaged households29. Moreover, recent evidence indicates that universally provided high-quality early care and education programmes reduce learning gaps between children from higher and lower socioeconomic status households30.
Given this, it is unsurprising that longitudinal studies show strong evidence for cognitive, social, and economic returns to high-quality early care and educational programmes30. For example, expanded pre-primary programme attendance for Argentinian children aged 3–5 increased primary school language and mathematics scores by 0.3 and 0.2 standard deviations (SD), respectively, for both boys and girls31. Adults in 12 LMICs who had attended early care and education programmes stayed in school on average 0.9 years longer, controlling for family background and other factors32.
We undertook new analyses of the value of pre-primary school, using a sample of 430,000 children from 73 middle- and high-income countries (Supplementary Table 1) surveyed in the 2018 Programme for International Student Assessments (PISA)33.