It’s a fair question and people tend to answer it with yes. This experiment mentioned on Freakonomics is far from finished, but seems to have very promising results, one to watch!

From the blog post:

Just thirty miles south of Chicago we started working with the Chicago Heights school district (which is demographically and economically identical to Chicago) and we found donors willing to invest in our idea in Ken and Anne Griffin. Then we went ahead and built two pre-schools and a parent academy and randomized families into a control group, a pre-school program, or a program that would work with parents to improve their efforts in raising their children.

How’s it going? Well, the experiment is still in the early stages, but the results so far have been very promising. Students in the two preschools are now doing better than the average child across the nation. These results are astonishing, given the fact that Chicago Heights preschoolers lagged severely behind the average before we started the program.

The children whose parents are in the Parent Academy haven’t seen such stark growth in their test scores, but perhaps most promising is that the growth that did occur persists. Children in the pre-school program seem to have a nasty habit of forgetting what they learn over breaks like summer vacation.