Comparing the squared multiple correlation coefficients of non‐nested models: An examination of confidence intervals and hypothesis testing

The performance of the asymptotic method for comparing the squared multiple correlations of non‐nested models was investigated. Specifically, the increase in a given regression model's R² when one predictor is added was compared to the increase in the same model's R² when another predictor is added. This comparison can be used to determine predictor importance and is the basis for procedures such as Dominance Analysis. Results indicate that the asymptotic procedure provides the expected coverage rates for sample sizes of 200 or more, but in many cases much higher sample sizes are required to achieve adequate power. Guidelines and computations are provided for the determination of adequate sample sizes for hypothesis testing.     

Cross-modal interactions in the experience of musical performances: physiological correlates

This experiment was conducted to investigate cross-modal interactions in the emotional experience of music listeners. Previous research showed that visual information present in a musical performance is rich in expressive content, and moderates the subjective emotional experience of a participant listening and/or observing musical stimuli [Vines, B. W., Krumhansl, C. L., Wanderley, M. M., & Levitin, D. J. (2006). Cross-modal interactions in the perception of musical performance. Cognition, 101, 80--113.]. The goal of this follow-up experiment was to replicate this cross-modal interaction by investigating the objective, physiological aspect of emotional response to music measuring electrodermal activity. The scaled average of electrodermal amplitude for visual-auditory presentation was found to be significantly higher than the sum of the reactions when the music was presented in visual only (VO) and auditory only (AO) conditions, suggesting the presence of an emergent property created by bimodal interaction. Functional data analysis revealed that electrodermal activity generally followed the same contour across modalities of presentation, except during rests (silent parts of the performance) when the visual information took on particular salience. Finally, electrodermal activity and subjective tension judgments were found to be most highly correlated in the audio-visual (AV) condition than in the unimodal conditions. The present study provides converging evidence for the importance of seeing musical performances, and preliminary evidence for the utility of electrodermal activity as an objective measure in studies of continuous music-elicited emotions.     

Sample diversity and premise typicality in inductive reasoning: evidence for developmental change

Evaluating whether a limited sample of evidence provides a good basis for induction is a critical cognitive task. We hypothesized that whereas adults evaluate the inductive strength of samples containing multiple pieces of evidence by attending to the relations among the exemplars (e.g., sample diversity), six-year-olds would attend to the degree to which each individual exemplar in a sample independently appears informative (e.g., premise typicality). To test these hypotheses, participants were asked to select between diverse and non-diverse samples to help them learn about basic-level animal categories. Across various between-subject conditions (N=133), we varied the typicality present in the diverse and non-diverse samples. We found that adults reliably selected to examine diverse over non-diverse samples, regardless of exemplar typicality, six-year-olds preferred to examine samples containing typical exemplars, regardless of sample diversity, and nine-year-olds were somewhat in the midst of this developmental transition.     

Developing stimulus control of young children's requests to teachers: classwide applications of multiple schedules

Children may recruit their teachers' attention at undesirably high rates or at inconvenient times. Tiger and Hanley (2004) described a multiple-schedule procedure to reduce ill-timed requests, which involved providing children with two distinct continuous signals that were correlated with periods in which teacher attention was either available or unavailable. The current study extended the application of multiple schedules by evaluating the effectiveness of the procedure when implemented by private-school teachers in 3 elementary classrooms. Following the introduction of the multiple schedules, student approaches toward their teacher were maintained during desirable periods but were minimized during undesirable periods.     

Rapid facial reactions to emotional facial expressions in typically developing children and children with autism spectrum disorder

Typical adults mimic facial expressions within 1000 ms, but adults with autism spectrum disorder (ASD) do not. These rapid facial reactions (RFRs) are associated with the development of social-emotional abilities. Such interpersonal matching may be caused by motor mirroring or emotional responses. Using facial electromyography (EMG), this study evaluated mechanisms underlying RFRs during childhood and examined possible impairment in children with ASD. Experiment 1 found RFRs to happy and angry faces (not fear faces) in 15 typically developing children from 7 to 12 years of age. RFRs of fear (not anger) in response to angry faces indicated an emotional mechanism. In 11 children (8-13 years of age) with ASD, Experiment 2 found undifferentiated RFRs to fear expressions and no consistent RFRs to happy or angry faces. However, as children with ASD aged, matching RFRs to happy faces increased significantly, suggesting the development of processes underlying matching RFRs during this period in ASD.     

Differential stability and individual growth trajectories of big five and affective traits during young adulthood

Big Five and affective traits were measured at three assessments when participants were on average 18, 21, and 24 years old. Rank-order stability analyses revealed that stability correlations tended to be higher across the second compared to the first retest interval; however, affective traits consistently were less stable than the Big Five. Median stability coefficients for the Big Five increased from .62 (Time 1 vs. Time 2) to .70 (Time 2 to Time 3); parallel increases also were observed for measures of negative affectivity (median rs=.49 and .55, respectively) and positive affectivity (median rs=.48 and .57, respectively). Growth curve analyses revealed significant change on each of the Big Five and affective traits, although many of the scales also showed significant variability in individual trajectories. Thus, rank-order stability is increasing for a range of personality traits, although there also is significant variability in change trajectories during young adulthood.     

Stability and change in personality traits from late adolescence to early adulthood: a longitudinal twin study

We conducted a longitudinal-biometric study examining stability and change in personality from ages 17 to 24 in a community sample of male and female twins. Using Tellegen's (in press) Multidimensional Personality Questionnaire (MPQ), facets of Negative Emotionality (NEM) declined substantially at the mean and individual levels, whereas facets of Constraint (CON) increased over time. Furthermore, individuals in late adolescence who were lowest on NEM and highest on CON remained the most stable over time, whereas those exhibiting the inverse profile (higher NEM, lower CON) changed the most in a direction towards growth and maturity. Analyses of gender differences yielded greater mean-level increases over time for women as compared to men on facets of CON and greater mean-level increases for men than women on facets of Agentic Positive Emotionality (PEM). Biometric analyses revealed rank-order stability in personality to be largely genetic, with rank-order change mediated by both the nonshared environment (and error) as well as genes. Findings correspond with prior evidence of a normative trend toward growth and maturity in personality during emerging adulthood.     

Expect the unexpected: failure to anticipate similarities leads to an intergroup forecasting error

People often expect interactions with outgroup members to go poorly, but little research examines the accuracy of these expectations, reasons why expectations might be negatively biased, and ways to bring expectations in line with experiences. The authors found that intergroup interactions were more positive than people expected them to be (Pilot Study, Study 1). One reason for this intergroup forecasting error is that people focus on their dissimilarities with outgroup members (Study 1). When the authors focused White participants' attention on the ways they were similar to a Black participant, their intergroup expectations changed to match their positive experiences (Studies 2 & 3). Regardless of focus, Whites expected to have pleasant intragroup interactions, and they were accurate (Study 4).     

Why positive information is processed faster: the density hypothesis

The authors postulate and show a speed advantage in the processing of positive information and hypothesize that this advantage is caused by the higher density of positive information in memory: Positive information is more similar to other positive information, in comparison with the similarity of negative information to other negative information. This "density" hypothesis is supported by multidimensional scaling of evaluative stimuli and response latency experiments. The relevance and explanatory power of the hypothesis is demonstrated by secondary data analyses of prior research in the evaluative priming paradigm. The final discussion is concerned with further theoretical implications of the density hypothesis, its generality and limitations, and its relation to other theoretical conceptions and applications.