Twins, interaction of heredity, bio-social handicaps, and family parentingstyles

The authors stated that mothers of dizygotic twins mostly characterise one of them as generally problematic, while monozygotic twins appear to mothers usually both as problemless. This fact suggest that the differences betwee n monozygotic and dizygotic twins are given not only by heredity but also b y the general problematicity (according to mother's judgement) what is prob ably influenced also by other conditions than the hereditary ones. The stud ies in twins hitherto did not take this fact into account and that is why t hey probably somewhat overestimate the role of heredity in the formation of personality traits. Among the variables supposed by the authors to be able to indicate the bio-social handicap of the child, the mother's judgement c oncerning the general problematicity of the child shows the relative closes t relation to the traits of the child's personality. The case studies indic ated in detail some partial data concerning the mutual relations of heredit y, bio-social handicaps and family parenting styles what can become the the me of further research.