Brooke Schindler is psyched at the beginning of each new school year. "There's a special energy because the students are excited to learn new things," says the fourth-grade teacher at Franklin Elementary School, in Wausau, Wisconsin. But first, she has to spend valuable class time reviewing the material the kids learned in third grade. "It's as if their minds start to prune away the knowledge they didn't use over the summer," says Schindler.
She's not the only educator who feels that way. A Columbia University study estimates that elementary-school teachers spend up to eight weeks re-teaching what kids forgot over the break. This phenomenon is known as "summer slide."
"Think of the brain as a muscle," says Earl Martin Phalen, founder of Summer Advantage USA, a nonprofit that provides enrichment programs for disadvantaged youths in Indianapolis, Indiana. "When you don't use it, you lose it."
Most experts aren't suggesting that summers filled with beach trips and picnics should go the way of daily gym. But let's be real: When the school calendars were created a century ago, kids needed July and August off so they could help out around the farm; today, the only farming most kids do is on FarmVille.
"Too many kids turn much of their summer into a video-game or Internet marathon," says Harris Cooper, Ph.D., chair of the psychology and neuro-science department at Duke University, in Durham, North Carolina. "Summer's become a wasteland for them and a time when parents scurry to provide their children with mental stimulation."