Preschool vs. No Preschool

When I used to work with younger kids (age 3-5) at the local YMCA, I noticed how many of the parents could not afford preschool. They were in the program at the YMCA because there was financial aid for those programs for their children. However, the day-care was not up to the standards that a well run preschool was. 

As I watched these kids grow, I noticed how the kids who did go to preschool had more- I do not want to say self-control, but self-control. What I mean is that the kids in preschool knew the discourse of a school-type program. They knew to raise their hands, sit quietly (or at least quieter), and not push and shove the other kids. Of course, there are other factors such as socioeconomic statuses as well, but I thought it was interesting at the least. 

My hypothesis is that the kids that were currently enrolled in preschool were more familiar with the expectations of school, so they were not jolted into a new set of rules and regulations like some children that had not gone to preschool were.