psychology_Sons_(2003)

328 Abnormal Psychology

and defecation, and so forth. The sheep from which the thy-
roid gland had been removed, however, did not show these
effects. Liddell (1944) concluded that the critical element in
the experimental neurosis was not the difficulty in making
discriminations, but the emotional reaction to the threat
posed by the electric shock. Although Liddell performed no
human studies, he made the theoretical link with human neu-
roses explicit in his reports of his animal work. W. H. Gantt
(1953) performed similar studies on dogs.

Experimental Neurosis and Approach-Avoidance Conflict

Other animal behavior studies were conducted within a
Freudian framework. They centered on the hypothesis that
a conflict between a motive toward pleasure (a “drive”) and a
fear of punishment (another “drive”) constituted the core
element of the psychodynamics of animal—and human—
neurosis. Clark Hull at Yale performed much of the initial
work. Hull took basic tenets of Pavlovian psychology and
sought to integrate them with certain Freudian concepts, with
a view to understanding how such conflicts might be reduced
by suitable environmental manipulations (Miller, 1944).
Within this framework other experimenters studied the effect
of variables designed to reduce the anxiety component of the
conflict, thereby permitting the emergence of the positive
(approach) component. These studies were attempting to dis-
cern “therapeutic” factors that might be applied to neurotic
human patients. Investigations using animals included the
effects of displacement and escape, Berkun (1957), Elder,
Noblin, and Maher (1961), Taylor and Maher (1959), and
many others. The paradigm was applied to many aspects of
human behavior, including verbal statements in psychother-
apy (Murray & Berkun, 1955), and neurotic behavior in gen-
eral (Phillips, 1956).
After 1960, this approach declined, partly because of
developing doubt about Freudian explanations of psy-
chopathology. Another reason was methodological con-
straints involved in generalizing from animals to humans and
increasing criticisms of the approach-avoidance model itself
(e.g., Atthowe, 1960; Maher, 1964). Although laboratory
animal research of this kind declined, the application of these
ideas to humans was to become one of the main themes of
behavior therapy.

Typologies of Mental Illness

The notion, embodied in the humor theory, that mental illness
proceeded from an imbalance of some internal biological
factor, survived for centuries. Its decline did not lead to the
abandonment of typology. New ones followed, each sharing

the assumption that normal personality included basic types,

each with specific biological balance, and each more liable to

a specific kind of psychopathology should the balance be

disturbed.

Pavlov

Pavlov provided one such typology. He theorized that behav-

ior, both normal and pathological, is determined by the inter-

action of three basic properties of the nervous system. These

are the strength of the excitatory and inhibitory processes, the

equilibrium of these processes, and their mobility. Pavlov ini-

tially based the typology upon observations of dogs in his

laboratory, but later extended it to humans.

Kretschmer and Sheldon

German psychiatrist and neurologist Ernst Kretschmer

(1888–1964) presented a theory of personality in which he at-

tempted to link psychological disorders to physical build. In his

1921 Körperbau und Charakter(published in English in

1925), he proposed three main body types: the asthenic (thin),

the athletic, and the pyknic (stout). Based on observations of

patients in mental hospitals, he concluded that schizophrenia is

linked to the asthenic, and manic-depression to the pyknic

body type. Although, some studies of psychiatric groups found

some support for the classification, significant criticisms pointed

to different reactions of others to people of varying body types,

and the effect of these reactions upon later behavior.

The basic idea behind his typology was developed more

quantitatively in the United States by William Sheldon

(1942). Sheldon also proposed a threefold classification

of components of body form derived from stages of embry-

ological development: the endomorphic component, with a

prominence of intestines and other visceral organs; the meso-

morphic component, with a prominence of bone and muscle;

and the ectomorphic, with delicacy of skin, fineness of hair,

and sensitivity of the nervous system. In an individual, each

component is measured on a scale of three and a body type

assigned by the three digits for each component. Sheldon

proposed temperamental classifications to correspond to the

morphological types. He published on this theme from 1927

to 1971, and in his later publications he reported findings

based on a study of patterns of psychosis as related to physi-

cal constitution.

Eysenck

Hans Eysenck (1947) developed a typology of personality

based in large part upon the Pavlovian model, together with