Introduction to the Special Section on Mixture Modeling in Personality Assessment

Latent variable models offer a conceptual and statistical framework for evaluating the underlying structure of psychological constructs, including personality and psychopathology. Complex structures that combine or compare categorical and dimensional latent variables can be accommodated using mixture modeling approaches, which provide a powerful framework for testing nuanced theories about psychological structure. This special series includes introductory primers on cross-sectional and longitudinal mixture modeling, in addition to empirical examples applying these techniques to real-world data collected in clinical settings. This group of articles is designed to introduce personality assessment scientists and practitioners to a general latent variable framework that we hope will stimulate new research and application of mixture models to the assessment of personality and its pathology.     

Social recognition memory: the effect of other people's responses for previously seen and unseen items

When people discuss their memories, what one person says can influence what another person reports. In 3 studies, participants were shown sets of stimuli and then given recognition memory tests to measure the effect of one person's response on another's. The 1st study (n = 24) used word recognition with participant-confederate pairs and found that the effect of confederate responses on participant responses was larger for previously unseen items than for previously seen items (omega(p) = .23). This finding was replicated in the 2nd study, which used photographs of cars (n = 24). In the 3rd study (n = 54), which used photographs of faces with participant pairs, the effect was also larger for unseen items. Results indicate that people rely more on other people's memories for unremembered objects than for remembered objects. This is important for both theories of memory and applications (e.g., witnesses talking, students studying together).     

Multilevel modelling: Beyond the basic applications

Over the last 30 years statistical algorithms have been developed to analyse datasets that have a hierarchical/multilevel structure. Particularly within developmental and educational psychology these techniques have become common where the sample has an obvious hierarchical structure, like pupils nested within a classroom. We describe two areas beyond the basic applications of multilevel modelling that are important to psychology: modelling the covariance structure in longitudinal designs and using generalized linear multilevel modelling as an alternative to methods from signal detection theory (SDT). Detailed code for all analyses is described using packages for the freeware R.     

Patients’ Views of Treatment-Focused Genetic Testing (TFGT): Some Lessons for the Mainstreaming of <Emphasis Type="Italic">BRCA1</Emphasis> and <Emphasis Type="Italic">BRCA2</Emphasis> Testing

This paper explores patients’ views and experiences of undergoing treatment-focused BRCA1 and BRCA2 genetic testing (TFGT), either offered following triaging to clinical genetics (breast cancer) or as part of a mainstreamed care pathway in oncology (ovarian cancer). Drawing on 26 in-depth interviews with patients with breast or ovarian cancer who had undergone TFGT, this retrospective study examines patients’ views of genetic testing at this point in their care pathway, focusing on issues, such as initial response to the offer of testing, motivations for undergoing testing, and views on care pathways. Patients were amenable to the incorporation of TFGT at an early stage in their cancer care irrespective of (any) prior anticipation of having a genetic test or family history. While patients were glad to have been offered TFGT as part of their care, some questioned the logic of the test’s timing in relation to their cancer treatment. Crucially, patients appeared unable to disentangle the treatment role of TFGT from its preventative function for self and other family members, suggesting that some may undergo TFGT to obtain information for others rather than for self.     

Why Naturalize Consciousness?

This paper examines the relevance of philosophical work on consciousness to its scientific study. Of particular concern is the debate over whether consciousness can be naturalized, which is typically taken to bear on the prospects for its scientific investigation. It is not at all clear that philosophers of consciousness have properly identified and evaluated the assumptions about scientific activity made by both naturalization and antinaturalization projects. I argue that there is good reason to think that some of the assumptions about physicalism and explanation made by the parties to the debate are open to serious doubt. Thus this paper is an invitation for those inquiring into whether consciousness can be naturalized to more carefully consider the expected payoff of such efforts.     

Memory conformity affects inaccurate memories more than accurate memories

After controlling for initial confidence, inaccurate memories were shown to be more easily distorted than accurate memories. In two experiments groups of participants viewed 50 stimuli and were then presented with these stimuli plus 50 fillers. During this test phase participants reported their confidence that each stimulus was originally shown. This was followed by computer-generated responses from a bogus participant. After being exposed to this response participants again rated the confidence of their memory. The computer-generated responses systematically distorted participants' responses. Memory distortion depended on initial memory confidence, with uncertain memories being more malleable than confident memories. This effect was moderated by whether the participant's memory was initially accurate or inaccurate. Inaccurate memories were more malleable than accurate memories. The data were consistent with a model describing two types of memory (i.e., recollective and non-recollective memories), which differ in how susceptible these memories are to memory distortion.     

Does syntax contribute to the function of duets in a parrot, Amazona auropalliata?

Complex acoustic signals in many animal species are characterized by a syntax that governs how different notes are combined, but the importance of syntax to the communicative function of signals is not well understood. Mated pairs of yellow-naped amazons, Amazona auropalliata, produce coordinated vocal duets that are used for territory maintenance and defense. These duets follow rules that specify the ordering of notes within duets, such as a strict alternation of sex-specific notes and a defined progression of note types through each duet. These syntactical rules may function to define sex-specific roles, improve coordination, and allow individuals to combine calls into meaningful sequences. As a first step toward understanding the functional significance of syntax, we conducted two separate audio playback experiments in which we presented nesting pairs with normal duets and duets with broken syntax (i.e., one of the syntactic rules was broken). In Experiment One, we reversed the order of female and male notes within note pairs while retaining the typical progression of note types through a duet. In Experiment Two we reversed the order of note types across a whole duet while retaining the typical female-male ordering within note pairs. We hypothesized that duets with broken syntax would be less-effective signals than duets with normal syntax and predicted that pairs would respond less to broken syntax than to normal duets. Contrary to predictions, we did not observe differences in response between treatments for any variables except latency to approach the speaker. After we combined data across experiments post hoc, we observed longer latencies to approach the speakers after playbacks of broken syntax duets, suggesting that pairs could differentiate between playbacks. These responses suggest that breaking one rule of duet syntax at a time does not result in detectable loss of signal efficacy in the context of territorial intrusions.     

An empirical examination of distributional assumptions underlying the relationship between personality disorder symptoms and personality traits

This article examines the relationship between personality disorder (PD) symptoms and personality traits using a variety of distributional assumptions. Prior work in this area relies almost exclusively on linear models that treat PD symptoms as normally distributed and continuous. However, these assumptions rarely hold, and thus the results of prior studies are potentially biased. Here we explore the effect of varying the distributions underlying regression models relating PD symptomatology to personality traits using the initial wave of the Longitudinal Study of Personality Disorders (N = 250; Lenzenweger, 1999), a university-based sample selected to include PD rates resembling epidemiological samples. PD symptoms were regressed on personality traits. The distributions underlying the dependent variable (i.e., PD symptoms) were variously modeled as normally distributed, as counts (Poisson, Negative-Binomial), and with two-part mixture distributions (zero-inflated, hurdle). We found that treating symptoms as normally distributed resulted in violations of model assumptions, that the negative-binomial and hurdle models were empirically equivalent, but that the coefficients achieving significance often differ depending on which part of the mixture distributions are being predicted (i.e., presence vs. severity of PD). Results have implications for how the relationship between normal and abnormal personality is understood. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Is It Lonely at the Top? An Empirical Study of Managers’ and Nonmanagers’ Loneliness in Organizations

Loneliness is often assumed to be an occupational hazard for senior-ranked members of an organization. However, most of what researchers hear about being "lonely at the top" is anecdote. This article provides empirical evidence from three separate studies assessing loneliness in managers and nonmanagers. Across all three studies, loneliness did not differ by managerial status. Managers were no more or less lonely than their nonmanager counterparts. This suggests that factors beyond seniority may be contributing to loneliness in organizational settings. Ideas for future research are discussed.