Control y Protección de las Turbinas de Vapor

As with any cross-sectional research, a main limitation of these studies is that although several associations are reported, causality cannot be inferred from these associations. Thus, the BASE study cannot report whether bullying involvement, as a bully, victim, or bully-victim, leads to the social and emotional attributes investigated, or whether these attributes result in adolescents adopting these roles. A third stage of the BASE Study was initially planned to be completed at end of the school year, for which the stage two participants would be asked to repeat the screening assessment and some of the stage two measures. The purpose of this would have been to provide some, albeit short-term, longitudinal findings to explore temporal relationships. However, recruiting schools took considerably longer than expected and the organisation of the study met with

restrictions due to timetabling, availability of computer rooms, and the exam

commitments of the older pupils. It was therefore logistically difficult to incorporate a third assessment stage before the end of the summer term, and this design plan was abandoned. Some longitudinal research on bullying and sociometric status has been conducted. For example, bullying has been found to facilitate social dominance during the transition from primary to secondary school (Pellegrini & Long, 2002), and

conversely popularity has been associated with subsequent bullying behaviour (Sentse, Veenstra, Kiuru, & Salmivalli, 2015b). However further longitudinal research is needed to explore the associations reported in this thesis.

Secondly, the participating schools were located within a relatively small geographical area, and therefore the sample may not be representative of all adolescents within the UK, or indeed worldwide. The schools recruited showed some ethnic diversity, however a sizeable majority of the sample were of White British origin. It is unclear whether geographical or cultural differences would substantially influence the results. For

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example cultural differences have been shown in emotion perception (Jack, Garrod, Yu, Caldara, & Schyns, 2012; Matsumoto, 1989), and in the experience of emotions; including intensity, duration, and control (Scherer, Wallbott, & Summerfield, 1986). However, the prevalence of bullying and ethnic diversity of the participants assessed in these studies, were similar to those reported from previous research involving children and adolescents in the UK (Tippett et al., 2013; Wolke et al., 2001a). The focus of this thesis was to explore the social and emotional attributes of those who perpetrate bullying, and findings were derived from group comparisons made within this sample of adolescents. Whilst the generalisability of these findings can be questioned, the

conclusions drawn from these studies are reported specifically in relation to the group difference in this sample.

Thirdly, a number of the measures used; i.e., the ambiguous photographs and the combined affective instability scale, were novel to this research, or consisted of a reduced set of items from the original scales. The items used for these measures were based either on the data obtained within pilot studies, or findings, including factor loadings, from existing studies. Although a good level of reliability was reported for most measures, some (i.e., the social situation vignettes), showed low levels of internal consistency. Overall, further validation of these measures is needed. It is also important to note that for many of these measures, the effect sizes reported for findings were relatively small overall, and therefore the ‘real-word’ effects of these findings may not be substantive.

It could also be argued that the bullying/victimisation scale is more a measure of

victimisation than of bullying perpetration. The behaviours described in this scale do not specifically address the imbalance of power important for defining bullying perpetration (Smith et al., 2002). Participants were not provided with a definition of bullying, nor was bullying mentioned throughout the study. Therefore, it is possible that participants responded to items; i.e., hitting, pushing or shoving others, in relation to an ‘equal’ behavioural exchange between peers. For example, two boys may repeatedly fight one another due to a mutual dislike for each other; however these boys may be of equal strength and standing (Felix, Sharkey, Green, Furlong, & Tanigawa, 2011). Therefore responses may be more an indication of aggressive behaviour and interaction between peers, rather than bullying specifically (Smith et al., 2002). A definition of bullying could

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have been provided, however this has been found to reduce rates of bullying and victimisation reported by young people (Kert, Codding, Tryon, & Shiyko, 2010).

Finally, the dependent measures in studies two and three were all based solely on self- reports, and may therefore be vulnerable to subjective errors (Yang et al., 2016). The data obtained from these measures may be affected by distortions in adolescents’ self- perceptions or by ‘jokester’ (intentionally false) responses (Fan et al., 2006). With regards to emotional traits and attributes, there may be value in obtaining data from multiple informants, i.e., peer, parents, or teachers, to reduce the risk of subjective biases. However this approach would not be suitable for the assessment of early social information processing, for which findings represent the subjective interpretations of an individual. Similarly, a limitation of study one was the potential risk of shared variance by using peer nominations for determining both the sociometric outcome variables and the bullying roles. As noted in this study however, the combined use of self- and peer reports in establishing these roles reduced the risk of shared variance from using peer nominations alone, and the under-reporting of bullying perpetration associated with self-report methods (Solberg & Olweus, 2003).

Thus, the use of both self- and peer-reported bully involvement is a main strength of this study. Overall, these two methods, despite each of their potential limitations, are thought to complement each other (Salmivalli & Peets, 2009). Self-reports address the subjective experiences of an individual that may often not be known or go unnoticed by the peer group, whereas peer nominations reduce the risk of individual bias (Cornell & Brockenbrough, 2004). This combined method of assessment had the overall

advantage of identifying a large enough number of bullies to be assessed in stage two, which allowed for sufficiently powered comparisons to be made between groups.

A substantial sample of bully-victims was also identified; which contradicts previous studies that typically report bully-victims to be the smallest group (Menesini et al., 1997; Pellegrini et al., 1999). However, the prevalence rates of bully-victims show large variations across reports, between 4 and 29% (Schwartz et al., 2001), and this could be due either to inconsistencies in the way in which bullying involvement is measured, or the criteria used to categorise participants to groups (Solberg et al., 2007). Typically, higher prevalence rates have been found in studies in which bullying involvement is assessed using a number of behavioural descriptions (Baldry & Farrington, 1998;

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Mynard & Joseph, 1997), rather than those who provide a definition of bullying and solely ask participants how often they have been bullied/bullied others (Boulton & Smith, 1994; Menesini et al., 1997). The former method was employed within the BASE study, and could account for the higher number of bully-victims identified than other reports. Nonetheless, the prevalence of bully-victims reported in this study is consistent with a number of previous studies (Austin & Joseph, 1996; Hanish & Guerra, 2004), and is also supported by findings that the least prevalent group is in fact the ‘pure’ bullies, rather than bully-victims (Winsper et al., 2012; Wolke et al., 2014). However, the inconsistencies in the way these roles are defined and measured should be considered when comparing findings across studies.

The direct comparisons of bullies, victims, and bully-victims, can be considered another strength of this research. Although these roles have been addressed previously in research, there is a lack of findings that have directly compared them. For example, a number of studies have investigated characteristics associated with bullying and victimisation by identifying differences between bullies and non-bullies only (or victims vs non-victims) (Zych et al., 2017). Understanding the differences between bullies, bully-victims, and victims, and also the ways they may differ to those uninvolved, is important to further knowledge of how these roles develop and are maintained over time. It may also help those in a position of responsibility, i.e., teachers, to identify those who are involved in, or at risk of being involved in, bullying within these roles.

As highlighted in chapter 9, to my knowledge, this is the first study to assess affective instability in relation to bullying involvement. The significance of this trait for emotional and psychological well-being should not merely be restricted to the study of borderline personality disorder or anxiety and depression, but it is likely to show relevance outside clinical domains. Given the associations found between victimisation and later BPD (Wolke et al., 2012) and depression (Copeland et al., 2013; Sansone et al., 2010; Zwierzynska et al., 2013), and difficulties with emotion regulation reported for victims (Frizzo et al., 2013; McLaughlin et al., 2009), affective instability may be an important aspect of emotional functioning with regards to bullying involvement. Further

longitudinal research is needed to identify whether affective instability is a precursor to or a symptom of being victimised in adolescence, or if this trait mediates the

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Finally, this research utilised several widely-validated measures; namely the Inventory of Callous-Unemotional Traits, the Interpersonal Reactivity Index, and the three scales used to generate the combined affective instability scale (i.e., Affective Lability Scale, Affective Intensity Measure, and the Affective Control Scale). The individual and demographic information that was collected during stage one also allowed for potential confounding variables to be identified and controlled for in the analyses for each study.