Heavy substance use (SU) and substance use disorders (SUD) have complex etiologies and often severe consequences. Certain personality traits have been associated with an increased risk for SU(D), but far less is known about personality changes related to SU(D). This review aims to synthesize the existing literature on this research question. A systematic literature search was conducted from November 2022 to February 2023 in PubMed, EbscoHost, and Web of Science. Peer-reviewed original papers on SU(D)-related personality changes were included. Of 55 included studies, 38 were observational population-based studies and 17 were intervention studies. Overall, personality and SU measures, samples, study designs, and statistical approaches were highly heterogenous. In observational studies, higher SU was most consistently related to increases in impulsivity-related traits and (less so) neuroticism, while interventions in the context of SU(D) were mostly associated with increases in conscientiousness and self-efficacy and lasting decreases in neuroticism. Findings for traits related to extraversion, openness, conscientiousness, and agreeableness were mixed and depended on SU measure and age. Studies on bidirectional associations suggest that personality and SU(D) both influence each other over time. Due to their strong association with SU(D), impulsivity-related traits may be important target points for interventions. Future work may investigate the mechanisms underlying personality changes related to SU(D), distinguishing substance-specific effects from general SU(D)-related processes like withdrawal, craving, and loss of control. Furthermore, more research is needed to examine whether SU(D)-related personality changes vary by developmental stage and clinical features (e.g. initial use, onset, remission, and relapse).

This study aimed to examine Dispositional, Adaptational, and Environmental (DAE) variables at the intersection of adaptive and maladaptive personality development as a conceptual replication of the DAE-model (Asendorpf & Motti-Stefanidi, European Journal of Personality, 32(3), 167–185, 2018). In a community sample of adolescents (N = 463; Mage = 13.6 years; 51% female) hypotheses-driven cross-lagged panel models were tested. Longitudinal associations between Dispositional (i.e., neuroticism, disagreeableness and unconscientiousness), Adaptational (i.e., social problems), and Environmental (i.e., perceived quality of the parent-child relationship) variables were investigated. The results partially support the DAE hypotheses. High levels of neuroticism, disagreeableness and social problems were found to predict the perceived quality of the parent–child relationship. In turn, the perceived quality of the parent–child relationship was found to predict levels of unconscientiousness and social problems. No mediation effects were found and, in contrast to DAE hypotheses, results did not indicate bidirectional influences between dispositions and adaptations. The results shed light on differential person–environment interactions that shape personality development and the importance of the perceived quality of the parent–child relationship. These findings provide insight in pathways of personality development, that may lead to personality pathology, and demonstrate the value of the DAE model as a structured guideline that provides testable hypotheses.

The article represents an empirical study of paternity as a male personality development factor in men. Consensus is emerging that responsible fatherhood entitles the father to establish paternity, be present in the child's life, share economic support, and be personally involved in the child's life in collaboration with the mother. Literature reviews on fatherhood yield numerous empirical studies of specific fatherhood behaviors, whereas theory and the “bigger picture” have been notably insufficient. In the present article, problems of fatherhood in modern society, methodological problems of studying fathering, and cultural specifics of fatherhood are discussed. In addition, in order to aid further study of the phenomenon, the theoretically developed and experimentally approved model of the structure of paternity and the description of a specially developed training for fathers are presented. A principal finding of this report is that fatherhood is socially determined and influenced by contextual forces within the family and the community. The absence of a father-figure is detrimental to child personality development. At the same time, fatherhood can be a factor of male personality development of the father.

This review paper has two major aims, first to synthesise recent research findings and conceptual developments in the field of psychological gerontology in Germany and in German language publications, and secondly, to argue that the field's research findings deserve greater attention, for both their substance and their relevance to social policy. The review focuses on three major fields of psychological gerontology: (1) cognitive development in old age; (2) personality development in old age; and (3) social relationships in old age. It highlights the major findings generated by German scholars since the 1990s. Although numerous and diverse, a common thread is the move away from a focus on the limitations and decrements of later life, and increased attention to the continuing capacities and developmental achievements of older people. The discussion elaborates the view that there is considerable merit in considering the broader social implications of these results. In conclusion, and from a general rather than disciplinary perspective, it is argued that there is a strong need for geropsychological research to be designed and interpreted with explicit attention to the cultural and social contexts in which the subjects live.

This is a follow-up study aiming to describe personality development of twins and possible differences at different ages. The investigation was conducted at the Mother Clinic in the Karolinska Hospital in Stockholm. This report describes the language development of 35 twin pairs at 9 months of age. The development values show that no greater differences exist for girls between twins and singletons. The language result is however lower. The boys, on the other hand, have considerably lower results both on total development scale and on the language scale.