Congratulations are due state Sens. Michelle Kidani and Jill Tokuda, Rep. Roy Takumi and other leaders for giving all of Hawaii’s families a chance at a high-quality preschool for their 4-year-old children.

It is long overdue and, once it is fully funded, a public preschool system will allow Hawaii to catch up with many other states that have taken this important educational step.

The value of universal access to quality early education, whether accessed in the public or private sector, has long been recognized as important to educational and social equity.

But contemporary neurological research is warning us that even a universal quality preschool system is not enough to level the field of play.

Neurological evidence indicates that a high-stress environment for young children can have devastating consequences for the very architecture of the brain, changing neurological functioning and the quantity of brain matter.

The startling discoveries were first announced by Harvard researcher Jack Shonkoff and Deborah Phillips (Georgetown University) in their 2000 book, “From Neurons to Neighborhoods: The Science of Early Childhood Development,” and numerous corroborating studies have multiplied in the past 16 years.

In further studies, Shonkoff has found that when toxic stress produced often by impoverished living conditions become excessive, the hormonal activity damages neural connections, weakens immune responses and alters the brain elements that affect memory, learning and emotional control.

Moreover, recent studies tie the neural deterioration directly to poverty. One study completed at six universities measured the brain activity of adults who had been poor at age 9 and found physical underdevelopment in parts of the brain that control emotions.

We are also finding that humans have a chemical reaction to stress that at first protects us from damage. But the defense is limited. If a young child whose brain is still forming is exposed to constant stress from things like domestic violence, hunger, prenatal drug abuse and lack of stable nurturing and attention, the overloaded mechanism fails and the brain is adversely affected.

Supplemental sociological research also demonstrates how common child neglect is among the poor. Instability in housing and employment, greater vulnerability to crime and toxic health conditions, hunger and less access to pre-natal and post-natal care make large differences in a child’s life chances.

In Hawaii, the state Department of Human Services and nonprofits serving families know that early positive intervention in a child’s life is critical to mitigating the damage done by poverty.

With often-inadequate funding, developmental specialists are providing home visitations by health and educational specialists, parent counseling, treatment of substance abuse and encouraging reading and language development in even pre- literate toddlers.

But the biological research is telling us that poverty, more than genes or culture, is causing poor health, low educational attainment and neural malfunctions. Only effective poverty reduction can correct the problems, which will be so costly for society now and in the future.

In the midst of deceasing social mobility and growing inequality, we need to bolster support for Medicaid, food stamps, the earned income tax credit and the child tax credit, while considering direct cash distribution to America’s poorest families.

All of this needs to take place while bolstering a more vibrant economy. The very social stability we have taken for granted may well be at stake.

Perhaps we would be better to measure the health and education of our youngest children before finding America — or Hawaii — exceptional.