392 Forensic Psychology
legal settings, (b) the effects of the law on the practice of psy-
chology, and (c) research and scholarly inquiry as applied to
legal issues” (Hess, 1999, p. 24). Elsewhere, Hess noted the
difficulty of defining forensic psychology, as he asked, “Is
there a forensic psychology? Or, Is there a set of associated
forensic psychologies? This is a crucial issue facing us”
(Hess, 1996, p. 239).
The second popular definition of forensic psychology is
more circumscribed, focusing on the clinical aspects. Many
psychologists define forensic psychology more narrowly to
refer to clinical psychologists who are engaged in clinical
practice within the legal system. The distinction here is be-
tween psychologists who bring scientific information to the
courts for their consideration in cases and psychologists who
evaluate individuals and testify about them in reference to a
legal question.
The second question, concerning when forensic psychol-
ogy began, also has a broad and narrow definition. A broad
perspective would see the starting point as that time when
psychological concepts—that is, notions of psychological
functioning—were first applied to address forensic questions.
One might qualify this by requiring that these concepts were
offered to courts by professionals. This definition would date
forensic psychology at least back to the eighteenth century
when physicians and neurologists testified in insanity cases.
The narrower view would contend that forensic psychology
cannot be said to have existed until there was a field called
“psychology.” It was not until the mid-twentieth century that
psychologists were routinely allowed to testify about insanity
and competency, roles that were the exclusive purview of
psychiatrists until then (Bartol & Bartol, 1999).
If one adopts the broad perspective, where and when did
forensic psychology begin? The beginnings of forensic
psychology could be identified at least as far back as the an-
cient Greeks, as Hippocrates (ca. 480 B.C.E.) identified two
forms of mental illness, melancholia and mania. The ancient
Romans also wrote about “madness” as a medical and legal
problem. Similarly, ancient Hebraic law stated that “idiots”
and “lunatics” should not be held criminally responsible for
their acts because they could not distinguish right from
wrong (Maeder, 1985). The issue of madness received in-
creasing scrutiny over the centuries. By the thirteenth cen-
tury, the policy in England was to use the regular system of
prosecution to determine guilt and then use “the King’s
mercy” as a possible basis for avoiding the execution of an
insane convicted person. By the sixteenth century, in England
the idea that a madman should be acquitted, not convicted,
was widely accepted (Weinreb, 1986). The evolution of this
linkage between the law and the psychological concept of
insanity will be briefly outlined in the next section.
Where does all of this leave us? For historical complete-
ness, we will begin our analysis with an overview of the early
ideas about insanity held by legal systems. We leave it to the
reader to interpret this as either the early beginnings of foren-
sic psychology or a historical precursor to the later emergence
of forensic psychology as a subfield within psychology.EARLY ATTEMPTS TO APPLY PSYCHOLOGICAL
OR PSYCHIATRIC KNOWLEDGE TO THE
LEGAL SYSTEMConceptualizations of InsanityWhile the ancient Greeks and Romans pioneered the use of
notions of insanity in the law, later several widely publicized
cases in Great Britain laid the groundwork for the treatment
of insanity in the American and Canadian courts. Rex v.
Arnoldin 1723 involved the trial of Edward Arnold, also
known as “Mad Ned” Arnold, who shot and wounded Lord
Onslow, a nobleman closely aligned with the new British
king, George I. Justice Tracy elucidated what has become
known as the “wild beast” test, stating that in order for a per-
son to be found not liable for an offense, he must be “a man
that is totally deprived of his understanding and memory, and
doth not know what he is doing, no more than an infant, than
a brute, or a wild beast.. .” (Walker, 1968, p. 56). Arnold was
found guilty and sentenced to death, but Lord Onslow inter-
ceded and Arnold remained in prison for life. Although the
defense did not call any medical witnesses, the judge ruled
that evidence about the defendant’s behavior after the crime
was admissible, thus paving the way for medical testimony
in future trials about the results of examinations of the de-
fendant performed after the crime. Finkel (1988, p. 3) as-
serted that this case was “the Anglo-American benchmark
case most commonly cited as the historical beginning of the
insanity defense.”
In 1800, James Hadfield attempted to assassinate King
George III. Hadfield had suffered a serious head wound while
fighting for the British against the French six years earlier. As
a result of his injury, part of his skull was missing, the
membrane of his brain was exposed, and he had been dis-
charged from the army due to insanity. Now he believed that
he had been instructed by God to kill the “evil” king, and he
stated that he knew he would be executed for his act. Since
he knew what he was doing and the consequence that would
follow, he was not insane according to the “wild beast” test.
However, Hadfield’s defense attorney, Thomas Erskine, ar-
gued instead that Hadfield was a “lunatic” whose actions
were caused by a “morbid delusion.” Given the grievousness