Since its creation in 1998, the Implicit Association Test (IAT) has become a commonly used measure in social psychology and related fields of research. Studies of the cognitive processes involved in the IAT are necessary to establish the validity of this measure and to suggest further refinements to its use and interpretation. The current thesis used ERPs to study cognitive processes associated with the IAT. The first experiment found significant differences in P300 amplitude in the Congruent and Incongruent conditions, which were interpreted as a reflection of greater equivocation in the Incongruent condition. The second experiment tested the task-set switching account of the IAT in much greater detail by analyzing each trial type separately. In the Congruent condition, all trial types elicited the same amplitude P300. Local probability, and the consequent checking and updating of working memory, was thought to be responsible for differences between trials of the Incongruent condition that required or did not require a task switch. The final experiment examined the role of working memory in the IAT by introducing obtrusive and irrelevant auditory stimuli. The results of Experiment 3 indicated that the introduction of an obtrusive and irrelevant auditory increment deviant has little overall effect on the IAT, and a similar effect on switch and no-switch trials within the Incongruent condition. This could have been because both the Congruent and Incongruent conditions of the IAT make such extensive demands on central processing resources that few are available to allow for the switching of attention, or it is possible that the IAT does not require significant updating of working memory. The usefulness of ERPs in the study of the IAT effect is demonstrated by the current research. In particular, the finding that behavioural results were not always consistent with the ERP results demonstrates that electrophysiological measures can complement traditional behavioural measures.

Exploring the relationship between prejudice and ethical decision-making within individuals that wish to pursue a career in the field of criminal justice has the potential to yield valuable insights on the ways that moral decisions may be impacted by extraneous factors. The objective of this thesis was to explore this relationship by means of quasi-experimental design and through examining 30 potential criminal justice candidates. Results suggested that significant associations between explicit racial attitudes and ethical decision-making are largely context-specific. Conversely, there was no significant relationship found between implicit racial attitudes and decision-making. In conducting this study, a better understanding of the role that explicit factors contribute within the decision-making process was revealed and a gap within the literature was identified. Also worthy of note, this study was the first known research inquiry into the relationship between both implicit and explicit attitudes and ethical decision-making within a Canadian criminological setting.

Background: In September 2005, scientific journals began requiring trial protocol registration to increase transparency and accountability. Objective: My primary objectives were: develop a database of linked protocols and publications for surgical randomized control trials (RCTs); estimate the proportion published; and determine the proportion exhibiting selective outcome reporting. Methods: A systematic search of the clinicaltrials.gov database was conducted identifying surgical RCTs, completed between 2006 and 2012. Protocols were linked with publications. Primary outcomes were compared. Results: We identified a cohort of 743 surgical RCT protocols. The proportion of registered trials which published their primary results was 0.49 (n=364). The proportion of selective outcome reporting was estimated to be 0.244, significantly lower than the previous estimate (p<0.001). Conclusion: More than half of the completed surgical RCTs were unpublished, and one quarter of those published selectively reported their primary outcome. This supports the notion that significant bias is present in the surgical literature.

This study examined how social anxiety, gender, and mode of presentation influenced miscommunication and perception of negativity in children’s interpretation of computer-mediated messages. The initial phase of the research involved developing and validating the stimuli for emotion recognition via presentation of various emotionally toned messages. Following preparation of the stimuli, the 98 participants (aged 8-12 years) in the main study were randomly assigned to one of three conditions: audio-visual, audio-only, and text message. The same emotionally toned messages were presented in each of these three conditions. Participants were instructed to select from a list of six emotions (happy, sad, disgusted, angry, surprised, scared) which emotion each message conveyed. Participants then rated how positively or negatively they perceived each sentence, using a 5-point Likert scale that ranged from very negative to very positive. Following the emotion recognition and Likert rating task, participants completed questionnaires that gathered information about social anxiety and attribution bias. Findings revealed that additional nonverbal and paralinguistic, as in the audio-visual or audio-only condition, allowed participants to more accurately identify the emotion being conveyed in the message, compared to the text message condition. This advantage was found for all emotions with the exception of happiness. For happy messages, participants were able to identify the intended emotion at above-chance levels regardless of mode of presentation. When making interpretations about angry messages, a significant three-way interaction was observed between sex, condition and social anxiety. Likert rating analyses revealed that condition, sex, and social anxiety played important roles in the interpretation of both ambiguous and unambiguous emotions, such as surprise and happiness.

The existing estimation techniques for grouped data models can be analyzed as a class of estimators of instrumental variable-Generalized Method of Moments (GMM) type with the matrix of group indicators being the set of instruments. Econometric literature (e.g. Smith, 1997; Newey and Smith, 2004) show that, in some cases of empirical relevance, GMM can have shortcomings in terms of the large sample behaviour of the estimator being different from the finite sample properties. Generalized Empirical Likelihood (GEL) estimators are developed that are not sensitive to the nature and number of instruments and possess improved finite sample properties compared to GMM estimators. In this thesis, with the assumption that the data vector is iid within a group, but inid across groups, we developed GEL estimators for grouped data model having population moment conditions of zero mean of errors in each group. First order asymptotic analysis of the estimators show that they are √N consistent (N being the sample size) and normally distributed. The thesis explores second order bias properties that demonstrate sources of bias and differences between choices of GEL estimators. Specifically, the second order bias depends on the third moments of the group errors and correlation among the group errors and explanatory variables. With symmetric errors and no endogeneity all three estimators Empirical Likelihood (EL), Exponential Tilting (ET) and Continuous Updating Estimator (CUE) yield unbiased estimators. A detailed simulation exercise is performed to test comparative performance of the EL, ET and their bias corrected estimators to the standard 2SLS/GMM estimators. Simulation results reveal that while, with a few strong instruments, we can simply use 2SLS/GMM estimators, in case of many and/or weak instruments, increased degree of endogeneity, or varied signal to noise ratio, bias corrected EL, ET estimators dominate in terms of both least bias and accurate coverage proportions of asymptotic confidence intervals even for a considerably large sample. The thesis includes a case where there are within group dependent data, to assess the consequences of a key assumption being violated, namely the within-group iid assumption. Theoretical analysis and simulation results show that ignoring this feature can result in misleading inference. The proposed estimators are used to estimate the returns to an additional year of schooling in the UK using Labour Force Survey data over 1997-2009. Pooling the 13 years data yields roughly the same estimate of 11.27% return for British-born men aged 25-50 using any of the estimation techniques. In contrast using 2009 LFS data only, for a relatively small sample and many weak instruments, the return to first degree holder men is 13.88% using EL bias corrected estimator, where 2SLS estimator yields an estimate of 6.8%.

Many of the symptoms characteristic of PTSD such as hypervigiliance towards threat, involve attentional processes. The first part of this thesis explored the role of attentional processes in the maintenance and treatment of PTSD. Although general models of anxiety give attentional processes central prominence cognitive models of PTSD (e.g., Foa & Riggs, 1993; Brewin, Dalgleish, & Joseph, 1996; Ehlers & Clark, 2000) assign an important role to trauma memory and place little or no emphasis on the role of attentional processes in maintaining symptoms. Models of anxiety have suggested that attentional bias is automatic (Mathews & Macleod, 2002) or strategic (Wells & Mathews, 1994). Wells' (2000) Metacognitive Model of PTSD is one of the few models to emphasis thinking style and attention rather then memory. In this model attentional bias is thought to be strategic in nature. The evidence reviewed supports a role of attention in PTSD and suggests it may be beneficial to modify this process. Two different attention techniques based on models of bias are reviewed.The second part of the thesis described a randomized controlled evaluation of attentional training technique (ATT; Wells, 1990) on traumatic stress symptoms in a sample of 60 university students, who had previously experienced a stressful life event. ATT is a technique used in metacognitive therapy to modify the control of attention. Participants were randomly assigned to either an ATT group (n = 29) or a control group (n = 31). An emotional attention set shifting task was included as an objective measure of attention. The results supported the hypotheses, ATT reduced intrusions and negative affect, increased self-report attention flexibility and modified performance on the attention set shifting task. The results are consistent with the metacognitive model of PTSD. Theoretical and clinical implications are discussed and the results add to studies suggesting positive effects of the technique across a range of disorders.The third part critically reflected on methodological and ethical issues from the above research study. The interpretation of the findings is limited by the student population. It is acknowledged that the results are preliminary in nature but it is believed that the study provides useful insights into the role of attentional processes in the development and treatment of traumatic stress symptoms and provides a basis for studies in the future.

Differential item functioning (DIF) can occur across age, gender, ethnic, and/or linguistic groups of examinee populations. Therefore, whenever there is more than one group of examinees involved in a test, a possibility of DIF exists. It is important to detect items with DIF with accurate and powerful statistical methods. While finding a proper DIP method is essential, until now most of the available methods have been dominated by applications to large scale testing contexts. Since the early 1990s, Ramsay has developed a nonparametric item response methodology and computer software, TestGraf (Ramsay, 2000). The nonparametric item response theory (IRT) method requires fewer examinees and items than other item response theory methods and was also designed to detect DIF. However, nonparametric IRT's Type I error rate for DIF detection had not been investigated. The present study investigated the Type I error rate of the nonparametric IRT DIF detection method, when applied to moderate-to-small-scale testing context wherein there were 500 or fewer examinees in a group. In addition, the Mantel-Haenszel (MH) DIF detection method was included. A three-parameter logistic item response model was used to generate data for the two population groups. Each population corresponded to a test of 40 items. Item statistics for the first 34 non-DIF items were randomly chosen from the mathematics test of the 1999 TEVISS (Third International Mathematics and Science Study) for grade eight, whereas item statistics for the last six studied items were adopted from the DIF items used in the study of Muniz, Hambleton, and Xing (2001). These six items were the focus of this study. / Education, Faculty of / Educational and Counselling Psychology, and Special Education (ECPS), Department of / Graduate

Behavioural economics has established that cognitive biases such as the overconfidence bias impact managerial decision-making. Literature has also shown that different levels of management require different skills, values and decision-making processes and styles. It would likely follow that cognitive biases would impact different levels of management in varying ways. This research seeks to expand on current literature in drawing on principles of behavioural economics to further investigate the overconfidence bias and its relationship with different levels of management. This research also seeks to explore whether cognitive ability or reflection can further explain any relationship between overconfidence and level of management. A sample of managers at professional services firms was surveyed using various assessments of overconfidence. Utilising statistical techniques, it was found that in fact there were differences in overconfidence between levels of management. Specifically, middle management appeared to display different overconfidence tendencies than upper and lower management levels. The relationship between cognitive ability, level of management and the overconfidence bias also appeared to be significant enough to warrant further investigation. The results also showed insight into problems with the current definitions of overconfidence. Based on the findings, this study concludes by providing several business and academic recommendations. / Dissertation (MBA)--University of Pretoria, 2012. / Gordon Institute of Business Science (GIBS) / unrestricted

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abstract: Recent research finds that there is significant variation in stock market participation by state and suggests that there might be state-specific factors that determine household stock market participation in the United States. Using household survey data, I examine how accounting quality of public companies at the state level affects households’ stock market participation decisions. I find that households residing in states where local public companies have better accounting quality are more likely to invest in stocks. Moreover, those households invest greater amounts of their wealth in the stock market. Cross-sectional tests find that the effect of accounting quality on stock market participation is more pronounced for less affluent and less educated households, consistent with prior findings that lacking familiarity with and trust in the stock market is an important factor deterring those types of households from stock investments. In state-level tests, I find that these household outcomes affect income inequality, which is less severe in states where high public-firm accounting quality spurs more stock market participation by poorer households. Conversely, in states where public firms have lower accounting quality, stock market participation among poorer households is less common, and a larger share of high equity returns accrues to richer households, exacerbating income inequality. / Dissertation/Thesis / Doctoral Dissertation Accountancy 2020