I recently had a chance to read this article:
Preschool children's development in classic Montessori, supplemented Montessori, and conventional programs
Angeline S. Lillard
Department of Psychology, University of Virginia, Charlottesville VA 22904-4400, USA
I put forth a particular paragraph that stands out for me:
It really says a lot about the Montessori Method - and the article goes on with more!
Theoretically, using Montessori materials would seem to exercise many aspects of executive function. For example, one of the ﬁrst Montessori materials with which a child is presented is the Pink Tower, a set of 10 wooden pink blocks ranging in size from a 1-cm cube to a 10-cm cube, with each cube 1-cm larger on each face than the previous one. In using this material, the children's task is to carry the cubes one by one from a display to a rug that they have previously rolled out on the ﬂoor, then rebuild the tower. To do this task entails planning. Second, each time a child chooses a block, she or he must do so with reference to its relation to all the other blocks: Is there another one in between the size of this one and the last one placed on the tower? This step requires working memory. Third, the child must inhibit the prepotent tendency to grab the closest block, and fourth, the child must pay strict attention to how he or she places each block on the one below it, creating a symmetrical tower. After building the tower, the child takes it down, returns the blocks to their stand by the shelves (in the proper order), and then tightly rolls up the rug and returns it to its place. This step requires ﬂexibility and task switching. Consider the difference between this and engaging with ordinary blocks. With ordinary blocks, one can do anything, without necessarily having any set plan, and one does not have to think about the blocks in relationship to each other. A preschool might not have a requirement that children put items away right after use (instead, there often is a single clean-up time right before going home), and there may well be no set way to arrange blocks when returning them to their place (often, they get put haphazardly into a large basket or box). The executive function demands are much reduced, and this difference in executive function demands applies across many other activities as well.