MMPI Modal Profiles in a Juvenile Delinquent Population

• DOI: 10.1177/009385488100800103
• Published date: 01 March 1981
• Author: Lawrence K. Pickett
• Date: 01 March 1981
• Subject Matter: Articles

MMPI MODAL
PROFILES IN A
JUVENILE DELINQUENT
POPULATION
LAWRENCE
K. PICKETT, Jr.
St. Louis County Juvenile Court
The MMPI results obtained from a sample of 245 adolescent males referred to the
evaluation unit of a Juvenile Court were submitted to a multivariate classification system
developed by Skinner (1977). The data were entered in the form of T-scores computed
from the means and standard deviations reported in Marks et al. (1974). The procedure
involves a Q-factor analysis of a double-centered matrix to produce modal profiles
determined by profile shape. By correlating individual subject profiles with the modal
profiles, six membership groups were formed. The cross products of each membership
group were then submitted to a second Q-factor analysis to produce subgroups based on
elevation and scatter parameters. The expected subgroups were not found. There was no
relationship found between group membership and either subject age or race.
ystems for placing entities into relatively homogenous
groups as aids in understanding their characteristics are
common
to the sciences. In the behavioral sciences, the classifi-
cation systems are intended to indicate the most appropriate
treatment and probable future behaviors of individuals. The basis
of these classification systems have ranged from tangible physio-
logical measures (Sheldon, 1942), to hypothetical constructs,
such as the developmental level of a portion of the personality
structure (Sullivan et al., 1957).
Standardized self-report inventories, such as the MMPI and
CPI, have been used as . aids both in making membership
decisions and in describing characteristics of the groups. Often
they are used as a dependent variable, with differences in
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individual scales or scale patterns being examined across diag-
nostic categories, which were based on demographic or behav-
ioral information. An alternate strategy is to form the groups on
the basis of profile similarity and then examine the demographic
and behavioral characteristics of the groups. Several volumes
have been written which use 2, 3, or 4 &dquo;point codes&dquo; or
combinations of elevations to aid in diagnostic efforts (Hathaway
&
Monachesi, 1961, 1963; Lachar, 1974; Marks et al., 1974).
These point codes can be used as the basis for forming diagnostic
groups which have relevance for treatment and outcome.
Although improving the utility of the profiles, the point code
approach makes use of only part of the information available in a
profile. As the analyses have improved in sophistication, total
profile configuration has been acknowledged to be more relevant
than isolated scale elevations for defining group membership
(Dahlstrom et al., 1975: 22). A
profile can be described in terms of
three characteristics: (1) elevation-the profile mean, (2) scatter
-the profile standard deviation, (3) shape-pattern of relative
high and low points when elevation and scatter are controlled. To
increase the amount of information used in forming the diag-
nostic categories, several strategies for considering total profile
configuration have been developed. Cronbach and Gleser (1953)
.
found that most...