Early Attempts to Apply Psychological or Psychiatric Knowledge to the Legal System 397testimony based on polygraph results in 1923 was rejected,
and the decision by the District of Columbia Circuit Court
inFrye v. United Statesproduced the venerable “Frye test”
for the admissibility of scientific expert testimony. The court
ruled that the proposed testimony must represent a position
that is generally accepted within the relevant scientific
community.
Marston (1920) also studied reaction times as indicators of
deception and reported that there was a type of person whose
reaction times during deception were shorter than while
telling the truth. Marston consulted with police and attorneys
on such matters, leading Bartol and Bartol (1999) to suggest
that he was one of the first consultants to the criminal justice
system, especially to law enforcement. Further, Marston
(1924) conducted some of the first research on the jury system.
In this research, he studied reactions to eyewitness testimony
by staging a series of events, after which witnesses reported
their memories in front of mock juries under conditions of free
narration, direct examination, and cross-examination. In dis-
cussing such research, Marston made a point that would still
be relevant to eyewitness research 75 years later. He noted that
“Experimentation upon the completeness and accuracy of
testimony, and of the findings of fact which might be based
upon the testimony, probably had its origin in an unconscious,
scientific wish to prove that our present juristic system is
incapable of achieving a decent degree of justice.” He added
that “For such observations and reports, therefore, we must
continue to depend upon human testimony. In light of this un-
deniable conclusion, it seems to me that the most profitable
subjects of psychological discussion and experiment are to be
found in the various possibilities of practical improvement in
the elicitation and use of normal, average testimony, rather
than in over-emphasizing its futility” (p. 29).
As we have seen, psychologists began to appear in some
western European courtrooms as expert witnesses at the
beginning of the twentieth century. There was some use of
psychologists as expert witnesses in the United States from
1921 to 1950; they testified mostly about cognitive processes
involved in witness memory or the psychology of crime and
criminal personality. The 1950s was labeled the “forensic
stage” by Loh (1981), because there was a dramatic increase
in the involvement of psychologists in the legal system, testi-
fying as expert witnesses in civil rights cases, about mental
disorders, and on the effects of pretrial publicity (Greenberg,
1956). The regular use of clinical psychologists as expert wit-
nesses on individual assessments of issues such as compe-
tency (to stand trial, to plead guilty, to waive rights), parental
competency, insanity, child custody, and the like became
commonplace only in the latter half of the twentieth century.
In a 1956 American Psychologistarticle, McCary asserted
that “An important problem in psychology today is the
legal status of the psychologist and his relationship to the
courts.... The use of the expert witness is a fairly modern
innovation in the field of legal evidence” (McCary, 1956,
p. 8). McCary supported moves toward the certification or li-
censing of psychologists, noting that “As long as any quack
can call himself a psychologist there is going to be resistance
to granting the mantle of the expert witness to psychologists
as a class” (p. 12).
The caution with which many courts regarded psycholo-
gists at the time may be illustrated by a 1955 decision of the
Texas Court of Criminal of Appeals in Watson v. State.The
judge wrote, “A psychiatrist is certainly best qualified to pass
upon a question of mental illness. However, we have consis-
tently accepted the testimony of medical doctors as experts.
We think that also of those qualified to give an opinion, supe-
rior to that of a layman, would be a practicing psychologist”
(p. 879). In addition to clinical psychologists making individ-
ual clinical judgments, social psychologists in this period
began to appear as experts in cases involving pretrial public-
ity and civil rights (Greenberg, 1956; Loh, 1981).
The involvement of psychologists in the legal system had
been only sporadic until the 1960s, when the social-political
activism of the times, with its emphasis on “social relevance,”
encouraged many psychologists to focus their research efforts
on the legal system. Interest in conducting legally relevant re-
search accelerated in the early 1970s, when it grew at an even
greater pace; indeed, in 1981 Loh (1981, p. 327) asserted that
since 1974, “there have been more psychologists doing more
empirical research on law-related matters that in all the pre-
ceding years combined.” The rate of law-related empirical
research has not slowed in the ensuing decades.
During this period, the scope of empirical inquiry ex-
panded beyond the traditional areas of eyewitness testimony
and evidence rules to encompass several fields relevant to
procedural justice. Loh (1981) posited that there were four
major areas: the effect of pretrial influences on the jury (e.g.,
pretrial publicity and pretrial identifications), selection of the
jury, presentation of testimony and of the law to the jury (e.g.,
judicial instructions), and decision making by the jury.Pre-1955 Psychological Writings about Psychology
and LawBy about 1930, nearly 50 articles relating to forensic psychol-
ogy (broadly defined) had appeared in American professional
journals; about one-third were written by German psycholo-
gists. A survey of these “legal psychology” articles by
Slesinger and Pilpel (1929) found that the psychology of testi-
mony (11 articles) and the detection of deception (10 articles)