Section IV., 1908. [179] Trans. R. S. C. 



X. — Thoughts and Facts on Right and L<^ft Handedness and an 

 Attempt to Explain Why the Majority of Men are Right Handed. 



By G. Prout Girdwood, M.D., M.E.C.S. (Eng.), F.C.S., F.I.C., 

 F.E.S.C Emeritus Professor in Chemistry Medical Faculty ol 

 McGill University, late Assistant Surgeon Grenadier Guards. 

 (Read May 26, 1908.) 



That the average man is right-handed is so well known, that it 

 would appear hardly worth noting the fact, but left-handed men are so 

 common that the question why are all men not right-handed must fre- 

 quently have been asked, and up to tho present date diligent search and 

 enquiry by the wi iter has not resulted in finding that anyone has pub- 

 lished a satisfactory reply; this is the excuse for bringing the subject 

 before you again. 



In the proceedings of this society are two able and exhaustive 

 articles upon right handedness, by the late Sir Daniel Wilson. 



In Section II, paper VII, page 119, Vol. No. 3, 1885, Sir Daniel 

 writes on " Paleolithic Dexterity." In this beautiful and interesting 

 article he goes over all the evidence of the stone implements of the paleo- 

 lithic age and of the stone arrow heads and tools, knives and daggers, 

 and the articles lie has been able to obtain or reach an account of, and 

 although finding some places where there seems to have been a larger 

 number of left-handed workmen, he still comes to the conclusion that in 

 those localities men at that period were as a, rule right-handed, some 

 were ambidextrous, and others were left-handed; as Sir Daniel himself 

 was naturally left-handed, hi;? opinion on the effect of education as a 

 reason for right-handedness is especially valuable, and he says that " my 

 " own experience as one originally left-handed is that in spite of very 

 *' persistent efforts on the part of teachers to suppress all use of the left 

 **' hand, I am now thoroughly ambidextrous, though still with the left 

 '•' the more dextrous hand." 



On page 130, Sir Daniel says, " But the entire number of left- 

 *■•' handed warriors of the tribe appears to have barely amounted to 2.7 

 " per cent. Out of 26,000 Benjamites, as we are told all warriors, 

 " there were 700 chosen men of the tribe, every one of whom was lef t- 

 " handed and could sling a stone at a hair's breadth and not miss. The 

 " instinctively left-handed is more dexterous in the true sense of that 

 " term. He is not only an exception to many right-handed men, he is 



