OF THE NATIONAL RESEARCH COUNCIL 135 



mittee thereupon appointed a subcommittee consisting of 

 Angell and Yerkes to attempt to make provision for the ten- 

 tative application of the Marston procedures by the Depart- 

 ment of Military Intelligence. 



Initial efforts to effect suitable arrangements through the 

 War Department failed. Thereupon attention was directed 

 to the Department of Justice, but early favorable response 

 failed to lead to definite arrangements. 



Finally Marston was commissioned in the Sanitary Corps 

 for psychological service and while in training at Camp Green- 

 leaf, Georgia, was able still further to supplement his earlier 

 laboratory and court observations. The method involves 

 the measurement of blood pressure during systematic cross 

 examining. Ordinarily the Tycos sphygmometer is used and 

 accurate record Is kept of the subject's verbal responses so 

 that variations In blood pressure as read at Intervals or as 

 recorded continuously may be studied in relation to the 

 verbal responses. 



The percentage of correct judgments, with reference to 

 guilt or innocence, reported by Marston is extremely high. 

 Thus in the case of the Greenleaf experiments, of thirty-five 

 men tested, nineteen without knowledge of the examiner had 

 chosen to steal, while sixteen were innocent and told the 

 truth under cross examination. On the basis of blood pres- 

 sure curves, Marston made thirty-four correct judgments, a 

 percentage of 97.1. These findings are supported by those 

 of previous carefully controlled laboratory experiments and 

 of several Instances of actual crime. 



The subcommittee appointed to thoroughly Investigate 

 the Marston procedures has not been able to complete Its 

 task and no report Is available for summary or publication. 



The deception tests, because of their applicational his- 

 tory, did not command the confidence of all members of the 

 Psychology Committee. To this fact may be attributed the 

 conservative position taken, which Involved first the desire 

 for trial under the conditions of real life, as contrasted with 

 the experimental laboratory setting, and finally, the recom- 

 mendation of tentative trial by the Government. It Is ex- 



