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PRELIMINARY STUDY OF CRIMINALITY AMONG TWINS (FROM BIOSOCIAL BASES OF CRIMINAL BEHAVIOR, 1977, BY SARNOFF A MEDNICK AND KARL O CHRISTIANSEN - SEE NCJ-47285)

NCJ Number
47289
Author(s)
K O CHRISTIANSEN
Date Published
1977
Length
20 pages
Annotation
CONCORDANCE IN RELATION TO SOCIAL BACKGROUND FACTORS IS ANALYZED IN UNSELECTED TWIN PAIRS FROM THE DANISH TWIN REGISTER.
Abstract
THE BASIC SAMPLE ANALYZED IN THIS STUDY COMPRISES 3,586 TWIN PAIRS BORN IN THE EASTERN HALF OF DENMARK BETWEEN 1881 AND 1910, IN WHICH BOTH TWINS WERE ALIVE AT LEAST UNTIL THE AGE OF 15 YEARS. ZYGOSITY OF THE TWINS STUDIED WAS DETERMINED BY MEANS OF A MODIFIED SIMILARITY TEST BASED ON A QUESTIONNAIRE. WHILE IT IS NOTED THAT CONCORDANCE RESULTS CAN BE NONCOMPARABLE DUE TO CHANGES IN THE PENAL CODE OVER THE YEARS, AS WELL AS IN THE ADMINISTRATION OF JUSTICE, IT IS CONCLUDED THAT NO RADICAL CHANGES TOOK PLACE DURING THE PERIOD COVERED BY THIS STUDY IN DENMARK. A NUMBER OF DIFFERENT CRIMINOGRAPHIC INDICES ARE COMPARED, SUCH AS TYPE OF OFFENSE, SERIOUSNESS OF SANCTION, NUMBER OF SANCTIONS, MAXIMUM PENALTY, AND CRIMINAL CAREER. SOCIAL BACKGROUND FACTORS THAT WERE CONSIDERED INCLUDED BIRTH YEAR, BIRTH PLACE, FATHER'S SOCIAL CLASS, AND SERIOUSNESS OF CRIME. OF THE TWINS STUDIED, 926 BELONGING TO 799 PAIRS WERE FOUND IN ONE OR BOTH OF THE REGISTERS FOR CRIME WHICH WERE SURVEYED. THE PAIRWISE RATE OF CONCORDANCE, WHICH HAS BEEN USED IN ALL THE PREVIOUS CHRIMINOLOGICAL TWIN TWIN STUDIES, IS FOR MONOZYGOTIC (MZ) MALES, 35 PERCENT; FOR DIZYGOTIC (DZ) MALES, 13 PERCENT; FOR MZ FEMALES, 21 PERCENT; AND FOR DZ FEMALES, 8 PERCENT. THE DIFFERENCES BETWEEN MZ AND DZ PAIRS AGREE WITH FINDINGS IN EARLIER TWIN STUDIES, BUT THE ABSOLUTE CONCORDANCE RATE FOR THE DANISH TWINS IS SIGNIFICANTLY LOWER THAN THAT FOR STUDIES CONDUCTED IN OTHER COUNTRIES. IN ORDER TO EVALUATE THE INFLUENCE OF BACKGROUND FACTORS ON THE CONCORDANCE RATES IN VARIOUS SUBGROUPS OF TWINS, IT IS NECESSARY TO COMPARE THE CONCORDANT PAIRS WITH THE TOTAL TWIN POPULATION WHEN THE TRAIT OCCURS WITH A RELATIVELY HIGH FREQUENCY, AS IS THE CASE WITH CRIME. THE PROBABILITY OF CRIME INCREASE FOR A TWIN WHOSE PARTNER IS CRIMINAL AS COMPARED TO THE GENERAL CRIME RATE OF THE TWIN GROUP IS CALLED THE 'TWIN COEFFICIENT.' THE TWIN COEFFICIENT IS EXAMINED IN RELATION TO CERTAIN CHARACTERISTICS OF THE POPULATION GROUP TO WHICH THE TWINS BELONG, AND IT IS DEMONSTRATED THAT THE SPECIFIC TWIN MILIEU, WHICH IS A PRODUCT OF INHERITANCE AND ENVIRONMENT, HAS DIFFERING INFLUENCES ON MZ AND DZ TWINS PAIRS AS WELL AS ON PAIRS WITH VARYING ENVIRONMENTAL BACKGROUNDS. THESE DIFFERENCES ARE ANALYZED IN TERMS OF HEREDITARY FACTORS INTERACTING WITH SOCIAL ENVIRONMENTS THAT PROVIDE DISTINCTIVE PATTERNS AND DEGREES OF RESISTANCE TO DEVIANT BEHAVIOR. THIS IS NOTED WITH REFERENCE TO URBAN VERSUS RURAL ENVIRONMENTS, OLDER VERSUS YOUNGER GENERATIONS, HIGHER VERSUS LOWER SOCIAL CLASSES, REARING FOR WOMEN VERSUS REARING FOR MEN, AND SANCTIONS AGAINST SERIOUS CRIME VERSUS SANCTIONS AGAINST MINOR OFFENSES. TABLES OF DATA AND ANALYSES ARE INCLUDED. (RCB)