A gentle reminder that mean does not imply modal behavior: Few are in-group biased in minimal groups

Previous research reports that people organized into newly formed, arbitrary groups (i.e., minimal groups) are on average in-group biased. However, that people on average behave in a certain way does not imply that most people behave that way. Here, I report four studies (n = 224) demonstrating in-group biased average behaviors driven by a minority of about 30% participants. Further, only 14% reported allocating resources in a group-biased manner because they “favored the in-group.” I investigate and discuss how methodological issues related to non-normally distributed data, not taking participants’ intentions into account, and using fixed response matrices can lead to overestimations of how widespread in-group bias is in minimal groups.     

Generalized multilevel structural equation modeling

A unifying framework for generalized multilevel structural equation modeling is introduced. The models in the framework, called generalized linear latent and mixed models (GLLAMM), combine features of generalized linear mixed models (GLMM) and structural equation models (SEM) and consist of a response model and a structural model for the latent variables. The response model generalizes GLMMs to incorporate factor structures in addition to random intercepts and coefficients. As in GLMMs, the data can have an arbitrary number of levels and can be highly unbalanced with different numbers of lower-level units in the higher-level units and missing data. A wide range of response processes can be modeled including ordered and unordered categorical responses, counts, and responses of mixed types. The structural model is similar to the structural part of a SEM except that it may include latent and observed variables varying at different levels. For example, unit-level latent variables (factors or random coefficients) can be regressed on cluster-level latent variables. Special cases of this framework are explored and data from the British Social Attitudes Survey are used for illustration. Maximum likelihood estimation and empirical Bayes latent score prediction within the GLLAMM framework can be performed using adaptive quadrature in gllamm, a freely available program running in Stata.gllamm can be downloaded from http://www.gllamm.org. The paper was written while Sophia Rabe-Hesketh was employed at and Anders Skrondal was visiting the Department of Biostatistics and Computing, Institute of Psychiatry, King's College London.     

Subjective probability intervals: how to reduce overconfidence by interval evaluation

Format dependence implies that assessment of the same subjective probability distribution produces different conclusions about over- or underconfidence depending on the assessment format. In 2 experiments, the authors demonstrate that the overconfidence bias that occurs when participants produce intervals for an uncertain quantity is almost abolished when they evaluate the probability that the same intervals include the quantity. The authors successfully apply a method for adaptive adjustment of probability intervals as a debiasing tool and discuss a tentative explanation in terms of a naive sampling model. According to this view, people report their experiences accurately, but they are naive in that they treat both sample proportion and sample dispersion as unbiased estimators, yielding small bias in probability evaluation but strong bias in interval production.     

Can attentional theory explain the inverse base rate effect? Comment on Kruschke (2001)

In J. K. Kruschke's (2001; see record 2001-18940-005) study, it is argued that attentional theory is the sole satisfactory explanation of the inverse base rate effect and that eliminative inference (P. Juslin, P. Wennerholm, & A. Winman, 2001; see record 2001-07828-016) plays no role in the phenomenon. In this comment, the authors demonstrate that, in contrast to the central tenets of attentional theory, (a) rapid attention shifts as implemented in ADIT decelerate learning in the inverse base-rate task and (b) the claim that the inverse base-rate effect is directly caused by an attentional asymmetry is refuted by data. It is proposed that a complete account of the inverse base-rate effect needs to integrate attention effects with inference rules that are flexibly used for both induction and elimination.     

Interviewing children with the cognitive interview: assessing the reliability of statements based on observed and imagined events

This paper investigated whether criteria stemming from the Reality Monitoring (RM) framework could be trusted to assess the reliability of statements obtained by the use of a cognitive interview (CI). Fifty-eight children, aged 10-11, participated. One-third watched a film about a fakir and were then interviewed according to a CI (n= 19). The remaining two-thirds made up a story about a fakir and were then interviewed according to either a CI (n= 21), or a structured interview (SI) (n= 18). The CI statements based on observed events contained more visual, affective, spatial and temporal information compared to CI statements based on imagined events. The CI statements based on imagined events did not differ from the SI statements based on imagined events. Considerable developmental work is recommended to turn the RM technique to a reliable test that could be used by practitioners.     

Basic information processing of neurotics and stables: an experimental ERP approach to personality and distractibility

The aim of the study was to investigate the effects of level of neuroticism on electrophysiological event-related potentials (ERPs) to different kinds of stimuli. The neuroticism items from the NEO-PI-R were administered to 168 female, right-handed undergraduates between 19 and 29 years of age. 20 highly neurotic and 22 highly stable persons underwent an ERP task that was designed to be a combination of an auditory P3a and a visual P3b oddball task. No significant differences in the P3a and P3b were detected. It is concluded that highly neurotic and highly stable persons do not differ in fast neurocognitive processing of neutral stimuli, and that cognitive differences between the groups may be located at another level in the sequence of information processing stages.     

Society for Personality Assessment 1971 Program

The aim was to study the validity of 2 personality instruments, the Health-Relevant Personality Inventory (HP5i) and the Junior Temperament and Character Inventory (JTCI), among adolescents with a substance use problem. Clinical interviews were completed with 180 adolescents and followed up after 12 months. Discriminant validity was demonstrated in the lack of correlation to intelligence in both instruments’ scales. Two findings were in support of convergent validity: Negative affectivity (HP5i) and harm avoidance (JTCI) were correlated to internalizing symptoms, and impulsivity (HP5i) and novelty seeking (JTCI) were correlated to externalizing symptoms. The predictive validity of JTCI was partly supported. When psychiatric symptoms at baseline were controlled for, cooperativeness predicted conduct disorder after 12 months. Summarizing, both instruments can be used in adolescent clinical samples to tailor treatment efforts, although some scales need further investigation. It is important to include personality assessment when evaluating psychiatric problems in adolescents.