Statistical Significance of the Contribution of Variables to the PCA solution: An Alternative Permutation Strategy

In this paper, the statistical significance of the contribution of variables to the principal components in principal components analysis (PCA) is assessed nonparametrically by the use of permutation tests. We compare a new strategy to a strategy used in previous research consisting of permuting the columns (variables) of a data matrix independently and concurrently, thus destroying the entire correlational structure of the data. This strategy is considered appropriate for assessing the significance of the PCA solution as a whole, but is not suitable for assessing the significance of the contribution of single variables. Alternatively, we propose a strategy involving permutation of one variable at a time, while keeping the other variables fixed. We compare the two approaches in a simulation study, considering proportions of Type I and Type II error. We use two corrections for multiple testing: the Bonferroni correction and controlling the False Discovery Rate (FDR). To assess the significance of the variance accounted for by the variables, permuting one variable at a time, combined with FDR correction, yields the most favorable results. This optimal strategy is applied to an empirical data set, and results are compared with bootstrap confidence intervals.     

Discrepancies between patients' and partners' perceptions of unsupportive behavior in chronic obstructive pulmonary disease

The literature on chronic diseases indicates that partner support, as perceived by patients, contributes to well-being of patients in either a positive or a negative way. Previous studies indicated that patients' and partners' perceptions of unsupportive partner behavior are only moderately related. Our aim was (1) to investigate whether discrepancies between patients' and partners' perceptions of two types of unsupportive partner behavior-overprotection and protective buffering-were associated with the level of distress reported by patients with chronic obstructive pulmonary disease (COPD) and (2) to evaluate whether the direction of the differences between patients' and partners' perceptions was associated with distress (i.e., whether patient distress was associated with greater patient or greater partner reports of unsupportive partner behavior). A cross-sectional study was performed using the data of a sample of 68 COPD patients and their spouses. Distress was assessed using the Hopkins Symptom Checklist-25. Patients' and partners' perceptions of unsupportive partner behavior were assessed with a questionnaire measuring overprotection and protective buffering. Distress was independently associated with patients' perceptions of protective buffering and discrepancies in spouses' perceptions of overprotection. Regarding the direction of the discrepancy, we found that greater partner reports of overprotection as compared with patient reports were related to more distress in COPD patients. Our study showed that patients' distress was associated not only with patients' perceptions, but also with discrepancies between patients' and partners' perceptions of unsupportive partner behavior.     

Understanding consumers' brand‐induced food taste perception: A comparison of ‘brand familiarity’ – and ‘consumer value – brand symbolism (in)congruity’ – accounts

Past research has shown that familiar brands can boost consumers' food taste experiences. On the other hand, more recent evidence suggests that the (in)congruity between consumer values and brand symbolism can affect the food taste perception. This study is the first one to integrate these two accounts into one single conceptual framework and to empirically evaluate their relative roles in explaining consumers' brand‐induced taste perception. Two experiments involving taste trials (blind vs brand‐cued sensory evaluation) were conducted. The first experiment analysed the brand familiarity effect, whereas the second experiment addressed also the taste perception of yogurts with differing brand symbolism amongst food consumers with distinct value orientations to find support for the (in)congruity effects. This research implies that congruity is not responsible for enhancing consumers' taste perception beyond the level that is produced by the brand familiarity. In contrast, the incongruity effect appears capable of neutralising the brand familiarity effect. Therefore, these two explanations may operate independently. More generally, this study speaks for the importance of incorporating consumer value – brand symbolism incongruity mechanism into food consumption studies; even owners' of strong food brands cannot trust the ability of their brands to boost a consumer's taste experience if there is no correspondence between his or her central values and brand symbolism. Thus, an objectively better taste is not necessarily decisive; satisfactory sensory quality can suffice if it is coupled with imaginative and daring brand marketing that delivers unique emotional and functional benefits for well‐defined food consumer target segments. Copyright © 2011 John Wiley & Sons, Ltd.     

Props,not pictures,are worth a thousand words: verbal accessibility of early memories under different conditions of contextual support

When they are tested nonverbally, even young children demonstrate long-term recall. There have been few studies of whether early memories later are verbally accessible; the results of those that exist are mixed. Inconsistencies may be due to differences in the contextual cues provided at the time of recall. In two experiments, children 13–20 months were exposed to multi-step sequences and tested for nonverbal recall after 3–6 months. At age 3 years, they were tested verbally, under varying conditions of contextual support: in the original laboratory with event-related props versus at home with photographs of the props (Experiment 1), and at home with props (Experiment 2). Children younger than 20 months at initial experience of the events did not demonstrate verbal recall. Children who were 20 months at the initial exposure recalled verbally, as long as they had physical props as cues, regardless of whether testing took place at home or in the laboratory. This research informs the conditions under which memories from very early childhood later can be recalled verbally. Copyright © 2004 John Wiley & Sons, Ltd.     

Peer Sociometric Status and Personality Development from Middle Childhood to Preadolescence

Sociometric status, the regard that other group members confer to an individual, is one of the most ubiquitous and behaviourally relevant attributes assigned to the person by the social environment. Despite this, its contribution to personality development has received little attention. The present three‐wave longitudinal study, spanning the age range 7–13 years (n = 1222), sought to fill this gap by examining the transactional pathways between peer sociometric status (measured by peer nominations) and Five‐Factor personality traits (measured by self‐ratings and parent and teacher ratings). Sociometric status prospectively predicted the development of extraversion. By contrast, agreeableness and neuroticism prospectively predicted the development of sociometric status. Furthermore, individual‐level stability in extraversion was associated with individual‐level stability in sociometric status. The results were robust across different sources of personality ratings. We argue that peer sociometric status in the school classroom is the type of environmental effect that has potential to explain personality development. Because of its stability, broadness, and possible impact across a variety of personality processes, sociometric status can both repetitiously and simultaneously influence the network of multiple inter‐correlated micro‐level personality processes, potentially leading to a new network equilibrium that manifests in changes at the level of the broad personality trait. © 2019 European Association of Personality Psychology