So here I am going out on a limb, largely unsupported by scientific data, but I am willing to speculate on what scientists will at some point know with certainty and in support of all those early educators who had noticed and reinforced the close connection between hand and brain. The movements of the hands shape the cognitive structures within the brain and its capacity for learning.
Healey quotes Dr. Phyllis Weikart, author of Round the Circle: Key Experiences in Movement
All this conversation is going on about cognitive development, but we've forgotten the child's body... The amount of physical activity since the turn of the century has declined seventy-five percent; children are not playing, and through play a great deal of active learning takes place. Children used to play in natural ways, with kids of different ages, outside, basically unsupervised by adults. Visual and auditory attention, bodily coordination--all were gained through that kind of play. This physical learning must take place before children start dealing with abstractions; it doesn't happen if children don't have those experiences.Healy notes: "Dr. Weikart has recently become fascinated by the question of how physical movement helps children develop an internal sense of "beat" that seems to correlate with reading and math abilities." But that beat only works if it's origins and making are in the child's own body. The dominance of externally imposed beat just doesn't do it. According to Dr. Weikart, "That constant verbal, visual bombardment, all it's doing is tuning children out. If we want to improve their attention, we've got to get them up, get them physically involved, turn them back in."
I suggest the rthyhm of saws and hammers for a start.