Nonshared environmental processes in social‐emotional development: an observational study of identical twin differences in the preschool period

Differences in mothers’ parenting behaviors toward their identical twin preschoolers were examined to identify nonshared environmental processes in social‐emotional development. The study included 62 pairs of 3½‐year‐old same‐sex identical twins. Indicators of each child’s social‐emotional development (temperament, prosocial behavior, behavior problems and noncompliance) and parenting environment (warmth and negativity, positive and negative control, responsiveness) were assessed using observers’, interviewers’, and parents’ ratings. Mothers treated their identical twins differently, and this differential treatment covaried in expected ways with identical twin differences in social‐emotional adjustment. The twin who received more supportive and less punitive forms of parenting was also higher in positive mood and prosocial behaviors and lower in negative mood and behavior problems when compared to her or his twin.     

Construct Validity of Parent Ratings of Inhibitory Control

Recent literature has emphasized the need to examine executive functions (EF) in children using multiple sources, including both parent rating and performance-based measures. Computerized Go/No-Go tests, including commercially available continuous performance tests (CPTs), represent one of the most commonly used methods of assessing inhibitory control—a variable central to the executive function construct. We examined the relationship between parent ratings of inhibitory control and CPT performance in two mixed clinical samples. Experiment 1 examined 109 children ages 6–18 using the Behavior Rating Inventory of Executive Function (BRIEF; Gioia, Isquith, Guy, & Kenworthy, 2000) and the Conners' CPT-II (Conners, 2000). In this sample, ratings on the BRIEF Inhibit scale (mean T-score?=?62.3) were significantly higher than the CPT-II commissions score (mean T-score?=?50.7; p < .0001); and the BRIEF and CPT-II scores were not highly correlated (r?=???.12). Experiment 2 examined a sample of 131 children ages 7–18 using the BRIEF and the Tests of Variables of Attention (TOVA; Greenberg, 1996). In this sample, parent ratings on the BRIEF Inhibit scale (mean T-score?=?56.8) were similar to TOVA commissions scores (mean T-score?=?58.6; p?=?.33), although still poorly correlated (r?=??.02). Factor analyses exploring covariance between BRIEF scales CPT-II variables (Experiment 1) and between BRIEF and TOVA (Experiment 2) yielded similar findings. In both experiments, all eight BRIEF scales loaded on a single factor, with no overlap with either the CPT-II or the TOVA. In mixed outpatient clinical samples, the BRIEF appears to measure different elements of inhibitory control than those assessed by computerized continuous performance tests.     

Making tools isn't child's play

Tool making evidences intelligent, flexible thinking. In Experiment 1, we confirmed that 4- to 7-year-olds chose a hook tool to retrieve a bucket from a tube. In Experiment 2, 3- to 5-year-olds consistently failed to innovate a simple hook tool. Eight-year-olds performed at mature levels. In contrast, making a tool following demonstration was easy for even the youngest children. In Experiment 3, children’s performance did not improve given the opportunity to manipulate the objects in a warm-up phase. Children’s tool innovation lags substantially behind their ability to learn how to make tools by observing others.     

THE FUNDAMENTALIST MINDSET: PSYCHOLOGICAL PERSPECTIVES ON RELIGION, VIOLENCE, AND HISTORY. Edited by Charles B. Strozier, David M. Terman, and James W. Jones, with Katharine A. Boyd. Foreword by Martin E. Marty. 274?pp. Oxford: Oxford University Press, 2010. $19.95

The following review essay explores the nature and characteristics of the fundamentalist mindset. The editors note that the fundamentalist mindset, wherever if occurs, is composed of distinct traits such as dualistic thinking, paranoia, and rage in a group context; an apocalyptic orientation that incorporates distinct perspectives on time, death, and violence; a relationship to charismatic leadership; and a totalized conversion experience. The review essay will explore these characteristics in brief, underscoring the major themes found in the authors?? exploration of fundamentalism and the psychological and historical underpinning of the pervading mindset.     

Tool innovation may be a critical limiting step for the establishment of a rich tool-using culture: a perspective from child development

Recent data show that human children (up to 8 years old) perform poorly when required to innovate tools. Our tool-rich culture may be more reliant on social learning and more limited by domain-general constraints such as ill-structured problem solving than otherwise thought.     

Minimodularity and the perception of layout

In natural vision, information overspecifies the relative distances between objects and their layout in three dimensions. Directed perception applies (Cutting, 1986), rather than direct or indirect perception, because any single source of information (or cue) might be adequate to reveal relative depth (or local depth order), but many are present and useful to observers. Such overspecification presents the theoretical problem of how perceivers use this multiplicity of information to arrive at a unitary appreciation of distance between objects in the environment. This article examines three models of directed perception: selection, in which only one source of information is used; addition, in which all sources are used in simple combination; and multiplication, in which interactions among sources can occur. To monocular spatial information, using all combinations of the presence or absence of relative size, height in the projection plane, occlusion, and motion parallax. Visual stimuli were computer generated and consisted of three untextured parallel planes arranged in depth. Three tasks were used: one of magnitude estimation of exocentric distance within a stimulus, one of dissimilarity judgment in how a pair of stimuli revealed depth, and one of choice judgment within a pair as to which one revealed depth best. Grouped and individual results of the one direct and two indirect scaling tasks suggest that perceivers use these sources of information in an additive fashion. That is, one source (or cue) is generally substitutable for another, and the more sources that are present, the more depth is revealed. This pattern of results suggests independent use of information by four separate, functional subsystems within the visual system, here called minimodules. Evidence for and advantages of minimodularity are discussed.     

Three gradients and the perception of flat and curved surfaces

Researchers of visual perception have long been interested in the perceived slant of a surface and in the gradients that purportedly specify it. Slant is the angle between the line of sight and the tangent to the planar surface at any point, also called the surface normal. Gradients are the sources of information that grade, or change, with visual angle as one looks from one's feet upward to the horizon. The present article explores three gradients--perspective, compression, and density--and the phenomenal impression of flat and curved surfaces. The perspective gradient is measured at right angles to the axis of tilt at any point in the optic array; that is, when looking down a hallway at the tiles of a floor receding in the distance, perspective is measured by the x-axis width of each tile projected on the image plane orthogonal to the line of sight. The compression gradient is the ratio of y/x axis measures on the projected plane. The density gradient is measured by the number of tiles per unit solid visual angle. For flat surfaces and many others, perspective and compression gradients decrease with distance, and the density gradient increases. We discuss the manner in which these gradients change for various types of surfaces. Each gradient is founded on a different assumption about textures on the surfaces around us. In Experiment 1, viewers assessed the three-dimensional character of projections of flat and curved surfaces receding in the distance. They made pairwise judgments of preference and of dissimilarity among eight stimuli in each of four sets. The presence of each gradient was manipulated orthogonally such that each stimulus had zero, one, two, or three gradients appropriate for either a flat surface or a curved surface. Judgments were made were made for surfaces with both regularly shaped and irregularly shaped textures scattered on them. All viewer assessment were then scaled in one dimension. Multiple correlation and regression on the scale values revealed that greater than 98% of the variance in scale values was accounted for by the gradients. For the flat surfaces a mean of 65% of the variance was accounted for by the perspective gradient, 28% by the density gradient, and 6% by the compression gradient. For curved surfaces, on the other hand, a mean of 96% of the variance was accounted for by the compression gradient, and less than 2% by either the perspective gradient or the density gradient.(ABSTRACT TRUNCATED AT 400 WORDS)     

Different speech-processing mechanisms can be reflected in the results of discrimination and dichotic listening tasks

The relative peakedness of diotic ABX discrimination functions for certain speech stimuli and the relative magnitude of the right ear advantage that they yield in dichotic listening tasks have been thought to be functionally parallel measures of speech processing. The results of the present study suggest that this is not always the case.     

Cross-series adaptation using song and string

The acoustic-auditory feature “risetime” has been claimed to underlie both the phoneticaffricate-fricative distinction and the nonphoneticplucked-string/bowed-string distinction. We used the perceptual adaptation technique to determine whether the risetime differences of the [d3a]-[3a] distinction would therefore be registered by the same mechanism that mediates risetime differences for the plucked-bowed distinction. Two continua were used, one of digitally modified natural speech and one of synthetic violin sounds, in which the risetime was varied across each set of tokens from 0 msec to 80 msec in steps of 10 msec. The speech was sung and the violin notes were synthesized with the same fundamental frequency, 294 Hz. Adaptation of the category boundaries was observed only when speech adaptors were tested with the speech continuum and when violin adaptors were tested with the violin continuum. When crossseries tests were performed (violin adaptors tested with the speech series, and speech adaptors tested with the violin series), no effect of adaptation was observed. This finding indicates that these speech and violin sounds, despite obvious acoustic similarities, do not share the same feature detectors.