Wichita eagle. [volume] (Wichita, Kan.) 1886-1890, 1888-12-08
AN APE COUNTS FIVE.
SUCCESS IN TEACHING MATHEMAT
les TO A CHlMPANZEE.

! A Psychological Distinction-How AMI
| mails Count Estimating by MusculA
| Sense-A Problem for Scientists.
/ About year ago began, with the assist
| ance of the keeper, to instrucs the chimpan-
zee at the Geological gardens in the art of
computation. The method adopted was to
ask her for one, two, three. four or five
straws, which she was to pick UP and hand
out from among the litter in her cage OF
course, no constant order was observed in
making these requests. but whenever she
handed number not asked for her offer was
refused. In this way the animal learned to
associate the numbers with their names.
Lastly, If more than one straw were askeS
for, she was taught 10 hold the others in her
mouth until the required number was con,
plete, and then TO deliver the whole at once.
This method prevented any possible error
arising from her Interpretation of vocal
tones-an error which might we'll have
arisen if each straw had been asked for sep
arately.
RARELY MADE A MISTAKE
After few weeks continuous instruction
the ape perfectly well understood what was
required of her, and up to the time when
left town, several months ago, she rarely
made a mistake in handing me the exact
number OF straws that / named. Doubtless
she still continued TO do so for her keeper
For instance, if she is asked for four straws
she successfully picks up three and puts them
in her mouth; then she picks up fourth and
hands over all the four together. Thus there
can be no doubt that the animal is clearly
able 10 distinguish between the numbers l, 3
3, and 5, and that she understands the name
for each. But as this chimpanZee is somewhat
caprlcious III her moods, even private visitors
must not be disappointed if they fail to be
entertained by an exhibition of her learning
"a caution which it seems desirable to add
as this is the first time that the attachments
of my pupil have been made known to the
public, although they have been witnessed
by officers OF the society and other biological
friends.
have sent these facts to you, sir, because
think that they bear ont the psychological
distinction between sensuous estimation and
intellectual notation. Any child, a year after
emerging from infancy and not yet knowing
its numerals, could Immediately see the
difference between five pigs and six pigs, and,
therefore, as your writer indicates, it would
be an extraordinary ct if savage were
with larger number of pigs the insufliciencv
of his Sensuous estimation would increase
with the increase of numbers until point
would be reached at which, if he were to
keep count at all, he would be obliged to re-
sort to some system of notation--tnat is TO
mark off each separate unit with a separate
nota, whether by fingers, notcheS or words.
HOW ANIMALS COUNT.
Thus there is counting and counting-ds-
tinguishing between low numbers by directly
approaching the difference between two
quantities Of sensuous perceptions, and dis
tinguishiug between numbers of any amount
by marking eacn sensuous perception with
separate sign. OF course, Ill the above in
stances OF animals counting, it must be the
former nstaod alone that is employed and
therefore / nave not sought to carry the ape
beyond the number five, lest | slould spoil
the results a,rUldy gained. But a careful
resc2rch a9s been made 10 find how far this
method caC be carried II the caae Of man.
The experiments consisted il ascertainins
the number II objects such as dots on
piece OF paOe.l which admit Of being stimuli
tapeoueiy estimated wIch accuracy. 1t was
found thai Jle number admits of being
largely increased by practice, until. with an
exposure TO Wow Of one seconds duration,
the estimate admits Of being correctly made
up To betwest twenty and thirty o. .ects.
In the case az the ape il IS astonishing over
hQw long t;,ae the estimate endures. SUP
posing, for instance, that she IS requested to
find five coioTad stTaws. she perfectly well
understands what is wanted, but as colored
straws are rare IN the litter she hes TO seek
about for the a, ana thus it takes her long
time to complete the number; vet sac re-
members how many she has successfully
found and put into her mouth, SO that when
the number Is completed she delivers it at
once. After having Consigned them to her
mouth she never looks al the strayvs and,
therefore, her estimate Of their NUMBER must
be formed either by the feelings of her
mouth or by retaining mental impression
of tho successive movements of her arm in
picking up the straws and placing them in
her mouth. Without being able to decids
positively in which of these ways she esti-
mates the number. | am inclined to think it
is in the latter. But, # ST., it is surprising,
as already remarked, over how long a time
this estimate by muscular sense endures.-
Mr. Romano in The London Times.