Elien Neimeijer

116 to explore the associations between the quality of group climate, aggression, coercion (chapter 3) and the interaction between group climate and work climate, as perceived by sociotherapists (chapter 5). Insights into group climate and work climate were obtained by conducting studies from the perspective of the client and the sociotherapists working with them. The data of these studies was collected at Trajectum, a secure forensic treat- ment facility for adults with MID-BIF and externalizing behaviour problems (i.e., aggres- sion or sexual offenses) and/or internalizing problems (e.g., self-injurious behaviour or suicide attempts), located in the northern and eastern part of the Netherlands. Summary of the chapters The first study (chapter 2) examined the psychometric properties of the Group Climate Instrument (GCI) for this target group (N = 189). Construct validity, reliability and con- vergent validity of the GCI were examined. We also examined the variability in perception of group climate between and within living groups. The model contained four first-order factors (support, growth, group atmosphere and repression) and a second-order factor overall climate, providing preliminary support for construct validity of the GCI. Relia- bility coefficients were good for all factors. Preliminary evidence for convergent validity was found in significant moderate associations between subscales and single item ratings for the factors of group climate. The intraclass correlation coefficients indicated that a considerate proportion of variance can be attributed to between-group differences. It was concluded that the GCI can be used to assess the perception of group climate for individuals with MID-BIF in forensic care settings, although further development of the GCI and replication of our findings seem necessary (see key finding one). In chapter three the associations between group climate, aggressive incidents and coercive measures were examined. Participants ( N = 248) were interviewed about their perception of group climate utilising the Group Climate Instrument. Data on aggressive incidents and coercive measures was retrieved from the facilities’ electronic database. A multilevel structural equation model was fitted in which variability in perception of group climate within and between living groups was examined. An open and therapeutic group climate was associated with lower levels of aggression within and between groups. A higher number of aggressive incidents were significantly associated with a higher number of coercive measures. The findings have implications for the understanding of