THE opening of Mayor Bill de Blasio’s universal pre-kindergarten program this week will give 53,000 children access to free, full-day pre-K in New York City, compared with 20,000 enrolled last year. This is well worth celebrating, and other cities and states should follow suit. But this investment in school preparation is not enough. If we want to close the income-based achievement gap, we need to begin much earlier.

Families are the ultimate pre-pre-school. Research in neuroscience and other fields has established that parents and caregivers provide a crucial foundation during the first few years of life. Our public policies, however, make it much harder for families, especially families living in poverty, to lay this foundation.

In my research, I have cataloged government policies that undermine parent-child relationships during early childhood. Our legal system, for example, destabilizes low-income, unmarried families, distracting them from parenting. Forty-one percent of children are born to unmarried parents. These parents are usually romantically involved when the child is born, but these relationships often end. Rather than help these ex-partners make the transition into co-parenting relationships, the legal system exacerbates acrimony between them. States impose child support orders that many low-income fathers are unable to pay, creating tremendous resentment for both parents. And courts are not a realistic resource for many unmarried parents, leaving them to work out problems on their own.

Our workplace protection laws likewise do too little to address the needs of families. The dearth of paid parental leave means that many parents have to choose between their job and bonding with their newborn. Our unwillingness to regulate the scheduling of part-time work means that some parents scramble daily to find child care. And our inability to substantially raise the minimum wage means that parents often have to work multiple jobs, limiting time at home.