AMBIDEXTERITY.

Gisborne Times, Volume XXV, Issue 2051, 30 November 1907, Page 4 (Supplement)

AMBIDEXTERITY.

In the course of a lechurc on “Dexitority and tho Bend Sinister/’ ■delivered at the Royal Institution, London, Sir James Crichton Browne, said, according to the “Weekly Times” report, that during tho last 2000 years thero had been innumerable eruptions of {ambidextral enthusiasm, and some five years ago ■a new crusade on behalf of ambidexterity bad been started. 'Ho held, however, that on tho large scale ambidexterity was impossible and undesirable, that it was by the superior skill of his right hand that man had forgotten himself the victory, and that- to try to undo liis dextral pre-eminence was simply to fly in the face of evolution. Righthandedness was a very old story; it was plainly discernible in the art of -Greece, Assyria, and Egypt, glimpses of it could he found among our ancestors in the Bronze Age, and in Palaeolithic times, and some observers bad detected foreshadowings of it oven among the lower animals. All nations, tribes, and races, civilised and savage, had in all times preferentially used not only one, but the same hand, and it was impossible to point to any civilised race manifesting any degree of eitherhandedness; the statement that the Japanese were by law and practice ambidextrous, lie could say, on the authority of B-aroii Komura, 'was without foundation. It was doubtful, indeed, whether . strictly speaioing, complete ambidexterity existed in any fully developed and civilised human beings, though sometimes very close approximations to it occurred; but among microcephulic idiots, in whom the small headedness was due to arrested development, left-handedness and ambidexterity had been found to reach a proportion as hig/h as 50 per cent. The source of right-handedness was much deeper than voluntary selection, and must be sought in anatomical configuration—in the structure and organisation of the brain, that initiated, directed, and controlled all voluntary movements. The brain had two hemispheres, of which the right presided over the left side of the' body, and the left over the right side, and it was clear that functional differences in the two hands were in some way connected with differences in the two ■hemispheres—differences not of weight or Mood supply, as had been suggested by some inquirers, but of convolutional development. Study of the speech centre in the third frontal or Broca’s convolution had thrown a flood of light on the subject of right-handedness, - for it had shown that damage ±o this eon volution in tlie left hemisphere deprived ■the rigid -handed man of speech, but left the left-handed man with speech, unimpaired, while in the left-hiand-ed mail the contrary held good. Here, then, thift-e was mi-e-sidednese of tlie hraim, assuredly not due to use and wont, or to any acquiredhabit or mechanical advantage. ±>ut the hand and the arm centres in the brain were intimately linked with tlie speech centres, and therefore it was only logical to infer that the preferential use of the right rrm and hand in volutary movements was also duo to tlie leading i>art taken by the left hemisphere. \Ve could not, he believed, get rid of our right-handedness, try liow we might. It was woven ill the brain; ■to change tho pattern the tissues must be unravelled. Ambidextral culture, useful enough in respect of some few rpecial movements in some few specially employed persons, must on a large scale tend, to confusion; and pushed towards that consummation which its ardent apostles said was so devoutedly, to be wished for, when the two hands would he able to write on two different subjects at the same time, tt must involve the enormous enlargement of our already overgrown lunatic asylums.