|hear, and forget
see, and remember
Do - and understand
Research shows that when someone acquires any level of dexterity - physical manual skill with any implements, then a significant development takes place in brain networks.
In essence, what happens is that very first human-type brain-change - from monkey to tool-using hominid - is being revisited by personal learning experience, and that this opens new networks, while strengthening the existing ones.
The outcome: by acquiring a manual skill or dexterity, from sweeping floors & scrubbing walls to sculpture or oil-painting, a human develops basic perceptions of cause and effect relationships and a real grasp of phenomena.
Corollary:- humans not acquiring a manual skill will not have those perceptions; they can be said to be judgementally primitive ref 01 - lacking in appreciations of cause and effect.
Few quantitative data gathered, however, the indications are that these developments, or indeed their avoidance, produce more noticeable (especially negative) results in human males, ref 02 probably because most females very early learn and use dexterity, from necessity or cultural habit.
Update 2013 - adding to references (below), new research by Liverpool University confirms that tool-making and language use the same area of brain networks - "consistent with theories that tool-use and language co-evolved and share common processing networks in the brain." [text copy]
Carl Sagan ref 03 was maybe prescient. Even without the research-data above he came to an almost identical conclusion in chapter VII of `Cosmos'.
He noted the early Greek thinkers - the `Ionians' - were real scientists producing sound work, sensible theories and accurate forecasting - with amazingly successful results.
They were practical people working as farmers / shipwrights / doctors & other `hands-on' trades. All these were forcing grounds for great science.
But later, when Greece became rich, with aristocrats owning many slaves, its scientists grew too grand to actually measure or experiment - and their "science" tended towards pompous waffle, with increasingly ridiculous results. ref 04
By then `science' was a prestige profession for the offspring of the elite, who, to paraphrase Sagan `are inclined to be contemptuous of physical experiment and have an unhealthy reverence for authority and received opinion, for these shore-up their own self-esteem'.
Sagan quotes science historian Benjamin Farrington's thesis:-
that success for the Greeks led to a conquering Empire - and slaves;
that the existence of numerous slaves in society meant that physical work was suddenly too `demeaning' for upper-class Greeks;
and that elite science therefore came to be based on dogma and unreal assumptions, leading to ridiculous results - bad science.
Does that sound familiar today?
Yes! - our own recent history is similar, even now the modern science-establishment demands conformist pseudo-science and `circular' arguments.
ref 05 & ref 06 & ref 07 & ref 08 & ref 09
Talking of today's `scientists' -
"... the educated classes tend to be the children of the wealthy, with a vested interest in the status quo, and are unaccustomed either to working with their hands or to challenging conventional wisdom."
Carl Sagan in "Cosmos"
Collapse of Societies / Civilizations.
It seems there was an earlier Mycenean civilization in the Aegean area which collapsed around 1500? BCE.
After a `Dark Age' of around 500 - 800 years the `Ionian' Greeks emerged as new thinkers & real scientists.
Much later aristocracy cast its blight on Greece and a slower but even more destructive collapse was begun (as subsequently happened to the Romans).
See Dark Ages
Institution: Institute of Higher Nervous Activity & Neurophysiology, Russian Academy of Sciences
Butlerov Str. 5a, Moscow 117865 Russia
Neural basis for reorganization of innate coordination during learning to use tools : role of the motor cortex and pyramidal system.
M.A. Maier1, P.A. Kirkwood2, K. Nakajima3 and R.N. Lemon2
1 INSERM U.483, Université Pierre et Marie Curie, Paris-6, France
2 Sobell Dept. of Neurophysiology, Institute of Neurology, UCL, London, UK
3 Dept. of Biological Control Systems, NIPS, Myodaiji, Okazaki, Japan
The importance and evolution of direct vs. indirect corticospinal connections for dexterity.
"Geschwind (1976), Kimura (1976), and Zangwill (1976) have all emphasized the role of the left hemisphere in the planning and control of purposive, sequential acts, and it has been argued that sequential aspects of perception are tied to the left hemisphere through its prior involvement with motor sequencing (Corballis 1980; Craig 1980)." ( Corballis, M.C. (1981) Towards an evolutionary perspective on hemispheric specialization. Behavioral and Brain Sciences 4: pp. 69)
2013 Update (see above) - `Shared Brain Lateralization Patterns in Language and Acheulean Stone Tool Production: A Functional Transcranial Doppler Ultrasound Study'
"Stone tool-making and cued word generation cause common cerebral blood flow lateralization signatures in our participants. This is consistent with a shared neural substrate for prehistoric stone tool-making and language, and is compatible with language evolution theories that posit a co-evolution of language and manual praxis." [text copy]