The Rock Island Argus and daily union. (Rock Island, Ill.) 1920-1923, 1922-07-05
Frederick Haskin's Letter
LIARS NDBLOOD PRESSURE

washinyton. D. C.. July 4.-6ome
day every prisoner At the bar may
have his saory scientincally tested
for truthfulness Blood pressure
has been tried and proved - .
gauge Of deception, and . method
has been evolved BY which m e.
pert can test With reasonable ex-
actness the truth Of the spoken
word
Thus q prisoner may recount
calmly . plausible aiibi for .
crime. Perhaps he shows NO Wis
ible symptoms Of fear or nervous
ness. But if he is not telling the
truth his blood pressure. over
which he has NO control. IL react
ing violently to the fear Of dis
coye-y. On the other hand. II he
is telling the truth, however fam
tastic, his blood pressure win bear
him out by remaining at a COM
paratively normal level.
The blood pressure deception test
has been developed to a practical
stage. 1t was used by the depart
me1t Of justice in connection with
wartime spy cases. II is being used
now by . criminologist Of the
Berkeley. Cal. police department
Here in Washington the man who
developed the test has just tried it
on a negro accused OF murder. Evil
1oV,o ic oDoinc$ fho ru.~oct k,t
tie test Indicates that his alibi is
correct. He is now being held
while other suspects are being
railed.
This illustrates the place which
the deception test will probably
come 70 hold in criminal investi-
CATION. It will not be taken as
absolute proof OF guilt or limo
cence. But in q case where the
evidence would convict a man in
spite OF his plea OF innocence the
deception test may lead to a fur
Their inquiry into other clues. With
| the test in use railroading a maa
TO Jail may be no longer q frequent
occurrence
| The pioneer OF the blood pres.
sure deception test is DR.. william
| n. Marston, professor of psychol-
ogy at the American university.
DR.. Marston says that there has
been some misunderstanding about
his work. He uses three different
kinds Of deception tests Of which
tie blood pressure test is the most
reliable. All Of the instruments
adapted for use in giving the tests
were invented some time ago for
various purposes. Dr. Marston ex-
plains that he is the inventor O!
the blood pressure test. but not O.
the instrument.
The Deceptive Complex.
Working at the Harvard labora.
tory in 1913. he evolved the theory
that blood pressure is an indicator
Of deception. Fear and anger
largely constitute the deceptive
complex. and these are the only
emotions that influence to any ex-
tent systolic blood pressure on
which the tests are based. DR..
Marston found by experiments that
If anyone attempts to deceive the
emotion Of fear influences his blood
pressure in definite ways. Even
If the possibility Of detection is re-
mote the organs respond somewhat
to an inherent fear. II is not nor
NAL to lie and this departure from
IL
pressure
/ Using an instrument which is at
tached TO the arm and which he
calls sphygbobanometer, the psy-
!chologist made numerous tests
which sustained his theories Tests
were made Of persons held by the
police department for theft, drug
taking. prostitution, forgery. and
bootlegging. After each test was
made DR.. Marston gave his verdict
as to the truth or falsity of the sub
iject's account. Then the investiga.
ton was continued by medical ex-
animation. questioning other per
sons involved. or by further detec-
tive work. 1t is claimed that the
blood pressure tests were invaria-
bly, substantiated by the corrobor-
alive evidence
DR.. Marston says that he has al
ways got 100 per cent satisfactory
results in making the tests himself
That is, for him the sphygmomano-
meter has proved 100 per cent re-
liable as a detector of deception
Other operators. less alert TO psy-
Geological factors in case, and
less experienced in making the ex-
aminations. have been getting from
so to 100 per cent satisfactory re-
suits.
1t is not simple matter to give
a deception test. From descrip-
tioa Of the method it is readily ap,
parent why an expert must give il
If it is to be of any value.
/ A women may have a normal
ihlood pressure Of 100. The sphyg-