Open main menu

Page:Popular Science Monthly Volume 44.djvu/624

This page has been validated.
608
THE POPULAR SCIENCE MONTHLY.

gives some details of the results of the experiments in which simple objects were used, extending over a period of four months (fifth to ninth in her life). The number of experiments at each sitting varied from ten to forty; the position of the child being reversed after half of each series.

Table I.
Date. No. of
series.
No. of ex-
periments.
Right
hand.
Left
hand.
Both
hands.
1890. February 10th to March 15th. 30 744 173 166 405
March 14tb to April 14th 25 623 134 141 348
April 14th to May 14th 25 546 213 130 203
May 14th to June 19th 16 274 57 131 86
Total 96 2,187 577 568 1,042

It is evident from Table I that no trace of preference for either hand is discernible during this period; indeed, the neutrality is as complete as if it had been arranged beforehand, or had followed the throwing of dice.

I then conceived the idea that possibly a severer distance test might affect the result and show a marked preferential response by one hand over the other. I accordingly continued to use a neutral stimulus, but placed it from twelve to fifteen inches away from the child. This resulted in very hard straining on her part, with all the signs of physical effort (explosive breathing, sounds resulting from the setting of the larynx, rush of blood to the head, seen in flushing of the face, etc.). Table II gives the results; the number in each series was very small—i. e., one to twelve (in one instance only):

Table II.
Date. No. of
series.
No. of
trials.
Right
hand.
Left
hand.
Both
hands.
1890. May 26th to June 10th 32 80 74 5 1


The same cases, distributed according to distance, give us Table III.

Table III.
12 inches. 13 inches. 14 inches. 15 inches.
Right hand 29 10 33 2
Left hand 5 . . . . . .
Both hands 1 . . . . . .

A comparison of II and III with I shows a remarkable difference—i. e., during the month ending June 15th, the child showed