‘All I Really Need to Know, I Learned in Kindergarten” isn’t just the title of an erstwhile best-seller — it’s a statement that’s been borne out by research.

The early years of school are a time when children develop the basic academic and social skills that prepare them to succeed later on. They learn how to get along with others. They’re introduced to the idea of right and wrong. They become familiar with the concepts that are key to keeping up with their peers in reading and math.

But too many kids — many of them impoverished — aren’t getting the learning opportunities they need. In Cumberland County, 4 to 8 percent of K-5 students miss at least 18 days of school a year, making it more likely that they’ll fall behind in class, become chronic absentees and never finish high school.

Now several southern Maine school districts are trying to change that, in a collaborative effort that recognizes that everyone has to get on board. Parents need to understand the importance of school attendance; schools need to develop solutions that target specific barriers to attendance. For the sake of our children’s academic advancement, these are lessons that can’t be learned soon enough.

Kids who regularly miss school in kindergarten lag their peers academically in first grade. By the end of third grade, they’re less likely to be able to read proficiently — placing them at greater risk of dropping out later on, researchers have found. What’s more, the whole class can end up paying the price as teachers repeat material to help chronic absentees catch up.

Poverty is a major factor in absenteeism. Kids from low-income families are less likely to attend school regularly than their higher-income classmates. If a family doesn’t have reliable access to health care, for example, young children may miss school because of a flare-up of a chronic condition like asthma. Language difficulties and lack of transportation and affordable housing also can be barriers.

Whatever the reason for chronic absenteeism, though, sound improvement practices are ones that target the community’s needs. In South Portland, where the highest truancy rate is among kindergartners, letters home didn’t work, one elementary school found. A more effective approach was a school-based family-style breakfast program. The result? Both fewer absences and fewer visits to the nurse’s office.

Outreach is critical to the success of the southern Maine effort; a new system alerts South Portland officials to frequent absences, prompting them to contact families and offer help. But the state as a whole must step up, too.

All school districts in Maine are required by law to offer kindergarten programs, yet attendance is voluntary. This not only doesn’t make sense, it also lends credence to the belief that kindergarten and the early grades aren’t as important as later grades. We know better than that, and it’s time for the state to commit itself to a level playing field for all Maine students.