Objectives: The current work formulated theoretical models for empirical testing based on three objectives: 1) to explore the associations of familial variables, specifically with regards to parental socialization, with two cognitive aspects of good thinking in children

- their informal reasoning skills and their epistemological beliefs, 2) to test the relation between these two competencies as epistemological beliefs have been found to enhance or constrain reasoning, and 3) to investigate if certain familial factors can significantly mediate the direct effects of socioeconomic status on these outcomes.

Participants: A sample of 1994 participants, 997 fifth-graders and 997 of their respective parents, from the longitudinal project FUnDuS “The role of familial support from parents in discourse and written competence in lower secondary schools” conducted in North-Rhine Westphalia, Germany, was used.

Measures: Questionnaires measuring the a) four Parenting Dimensions of Autonomy- support, Control, Responsiveness and Structure, b) Family Communication Patterns of Conversation- and Conformity-orientations, c) Epistemological beliefs of both parents and children, specifically beliefs in Justification by Authority, Personal Justification, and Simple and Certain Knowledge, and d) Socioeconomic status, were used. There were also two measures of evaluative reasoning competence in an everyday problem context: i) Reasons Evaluation and ii) Argument Differentiation.

Results: The data was analyzed with quantitative statistical methods and path analyses. The results show that amongst the parenting dimensions, only Control emerged as significantly detrimental to children’s informal reasoning skills and is associated with lower-level epistemological beliefs of knowledge being simple and certain.

Conformity-orientation within the family was also associated with poorer evaluative skills of children. More advanced parental epistemological beliefs, such as weaker beliefs in Simple and Certain Knowledge and Justification by Authority, were associated with more effective parenting practices of Autonomy-support, Responsiveness and

Structure, and with less use of Control. Additionally, parental epistemological beliefs were found to be significant predictors of children’s epistemological beliefs. The association between children’s epistemological beliefs and reasoning skills was also confirmed: higher-level beliefs were related to more skilled evaluative reasoning. Lastly, familial variables of parental control and conformity-orientation were found to be significant mediators of the direct effects of SES on children’s Reasons Evaluation skills and on their Simple and Certain knowledge beliefs.

Conclusion: The results are empirical evidence of first, the associations of parental epistemological beliefs and their parenting practices, and second, the significance that parental epistemological beliefs and parenting practices hold in the fostering of children’s reasoning skills and epistemological beliefs. To focus on skills of informal reasoning skills and epistemological beliefs is to focus on enhancing one's ability to think well. The implications of the results, limitations and future research directions are discussed.