In the study, the U.S. Department of Education tracked 20,000 children from kindergarten through fifth grade. It also tracked their parents and family routines and conducted periodic surveys and tests of the children's skills.

Some things mattered and some didn't in kids' test results. For example, it didn't matter if Mom stayed home from her child's birth to kindergarten. It didn't help to take the kids to museums. Head Start, while helping the kids adjust to school, didn't change the test grades either.

It did matter that parents were involved in local schools, members of PTAs, for example, and that English was spoken at home. TV didn't improve any of the tested skills, but neither did a computer in the home.

Children of parents with higher incomes showed better scores all through the preschool years, and kids born to older Moms did a lot better. Young single moms with limited education and income had children who scored 25 percentage points lower than children of two married, high-income parents.

Parents with higher education chose spouses with similar accomplishments and waited longer to have children. Their children tended to score higher on the tests. All of these factors result in more time, more feedback, more practice and more guidance for a child's performances.

Books made a difference. Children with 50 or more books in their home scored 5 percentage points higher than children with no books, but they were 5 points lower than children with 100 books at home. It seems odd that books to read helped math scores as much as reading scores. And there was no relationship between test scores and how often parents read to their child.

How do books help if parents don't read them to their kids? Why would a supply of kids' books help math skills? It turns out the books are a vehicle for attention, time together, support, talking and learning by example and instruction. Just reading the books isn't the crucial difference; it's the time parents spend with their children talking and looking at the books. Books provide an environment that rewards learning.

The study showed that the privilege gap is real. Not because of the money directly but because of time for relating to the children. The wealthy may be caught up in hectic schedules, but so are the not-so-wealthy. The question seems to be who will choose to spend time and conversation with their kids that will promote a respect for education?

Many parents tried "Culture Cramming," hauling the kids off to museums, libraries and concerts of Mozart. They hoped to help the kids toward the best preschool, the gifted and talented programs and entrance the best college. But it's not the museums that do it; grocery shopping was just as helpful.

Head Start and concerts were good for the mental health of the children, but the culture cramming didn't make a difference in test scores. Parent capability and dedication of time, help and support did.