ARE YOU LEFT-HANDED?

Manawatu Times, Volume LIII, Issue 6541, 24 February 1928, Page 3

ARE YOU LEFT-HANDED?

Left-handedness is surprisingly prevalent. Some authorities estimate it as high as 4 per cent, of the population; whatever tho total, males predominate largely lover females. Discussing the question in the December issue of tho Empire Eoview, Dr. Leonard Williams says our simian cousins are tiuly ambidextrous, but in man there .is no such thing as real ambidexterity. Speech is man s most salient characteristic, and it is possible that his dextrality is associated with this biologically peculiar development. Speech is represented on the 'left side of the brain. The muscular movements on the right side of the body are dependent upon centres on the left side of tho brain. This association between speech and rightsided muscular power is shown in the case of a “fit of apoplexy.” When the haemorrhage is into the right brain there is paralysis of the muscels on the left side of tho body, but no loss of speech. Another reason for dextrality! is that man toon learned the left side of his body was more vulnerable than his right. He did not know that his heart was on the left side, but experience taught him that peneterating wounds of tho left chest were more install-Ay fatal than similar wounds on the right chest, so he carried his shield it> his, left hand and wielded his weapon with his right. This greater activity of tho right arm muscles would mean a correspondingly greater development of the left brain centres so that, ultimately, not only the muscles of the right arm, but all the muscles on tho right side of the body, would become stronger than those on the left side. A largo number of left-handed

with stammering or other defects of that kind. The number is so large that the association cannot bo fortuitous. This would suggested that, when the speech centre is situated in the right brain instead of in the left brain, it fails to reach the normal degree of development. A great many theories have been advanced in explanation of righthandedness, some of which are very far-fetched. Inasmuch as there is no anatomical reason why people should favour the right hand, tho practice has boon confidently ascribed to tho imitation of a habit begun by chancQ and aimlessly continued. Some authorities have advanced tho idea that right-handedness is due to tho position of the infant in arms; by which one hand is rcstarined and the other allowed to develop. There are certain crafts, notably that of the surgeon, in which some aproach to ambidexterity is an outstanding advantage. It is said "chat the really expert pickpocket is always ambidextrous. Sir James Grichton-Brownc deprecates the attempt to educate people into ambidexterty. Ho says: “Wo cannot, I believe, not rid of our right-handedness, try how we may. Ambidoxtrial culture, useful enough in respect of some few special movements in some few specially employed persons. must, on tho large scale, tend to