Marital conflicts in the home when children are present versus absent

Characteristics of marital conflict when children (8-16 years) were present versus absent were compared on the basis of 47 mothers' and fathers' reports during a 15-day period. Mothers described 669 incidents of marital conflict, and fathers described 551 incidents. About two thirds of the conflicts occurred in children's absence. Contrary to predictions, conflicts in which children were present were more negative (e.g., more negative emotions, more destructive conflict tactics) and more often about children than were child-absent conflicts. Although parents may attempt to protect children from conflict exposure, children tend to be exposed to a relatively hostile and emotionally negative subset of the marital conflicts that occur in the home.     

Molecular analyses of the principal components of response strength

Killeen and Hall (2001) showed that a common factor called strength underlies the key dependent variables of response probability, latency, and rate, and that overall response rate is a good predictor of strength. In a search for the mechanisms that underlie those correlations, this article shows that (a) the probability of responding on a trial is a two-state Markov process; (b) latency and rate of responding can be described in terms of the probability and period of stochastic machines called clocked Bernoulli modules, and (c) one such machine, the refractory Poisson process, provides a functional relation between the probability of observing a response during any epoch and the rate of responding. This relation is one of proportionality at low rates and curvilinearity at higher rates.     

Multiple cues for quantification in infancy: is number one of them?

A review and synthesis of the literature on quantification in infancy and early childhood is provided. In most current conceptualizations, early quantification is assumed to be number based. However, the extant literature provides no clear-cut evidence that infants use number to perform quantitative tasks. Instead, new research suggests that quantification is initially based on nonnumerical cues, such as area and contour length, whether or not a task involves discrete items. The authors discuss the implications of these findings with respect to early quantification and its relation to later numerical development.     

What do infants know about continuous quantity?

We investigated infants' sensitivity to amount of continuous quantity and to change in amount of continuous quantity. Using a habituation procedure, Experiment 1 examined whether 6-month-old infants can distinguish between different amounts of liquid in a container. Infants looked significantly longer at a novel quantity than at the familiar quantity. Using a violation-of-expectation paradigm, Experiment 2 examined whether 9-month-old infants expect a change in amount when liquid is added to a hidden container which is already one-fourth full of liquid. Infants looked significantly longer at the impossible event than at the possible event. These findings indicate that infants are sensitive to amount, calling into question claims that infants have a quantitative mechanism which is exclusive to number.     

More than the Terrible Twos: The Nature and Severity of Behavior Problems in Clinic-Referred Preschool Children

The primary goals of this study are to describe the nature and severity of disruptive behavior problems in clinic-referred preschoolers from low-income environments and to explore the validity of DSM-IV disruptive disorders for young children. We examine the relation between DSM-IV symptoms, standardized behavior checklists, and observational ratings as a means of exploring measurement validity in this age group. Seventy-nine clinic-referred preschoolers (ages 2 through 5 years) from low-income environments were assessed. To examine whether clinic-referred preschool children have symptoms that are consistent with DSM-IV disruptive behavior disorders, parents were administered a semistructured diagnostic interview, modified for developmentally appropriate usage. In addition, parents completed the Child Behavior Checklist (CBCL) and children's behavior problems were assessed with observational ratings during parent–child interaction. Nearly half of the sample met criteria for conduct disorder, and three quarters met criteria for oppositional defiant disorder. Preliminary evidence for the validity of DSM-IV disruptive disorders in preschool children was demonstrated through association with CBCL scores, behavior ratings, and significant levels of impairment. Future efforts aimed at validating these diagnoses in preschoolers and implications for prevention are discussed.     

Sleep-related attentional bias in good, moderate, and poor (primary insomnia) sleepers

Evidence was sought of an attentional bias toward a highly representative object of the bedroom environment in good, moderate, and poor (primary insomnia) sleepers. Using a flicker paradigm for inducing change blindness, the authors briefly presented a single scene comprising a group of bedroom environment and neutral objects to participants and then briefly replaced this scene with an identical scene containing a change made to either a bedroom environment or a neutral object. In a 3 x 2 entirely between-participants design, change-detection latencies revealed a sleep-related attentional bias in poor sleepers but not in good sleepers. A possible bias in moderate sleepers was also revealed. It is suggested that attentional bias has a role in the perpetuation and possibly precipitation of primary insomnia.     

Identity and emergency intervention: how social group membership and inclusiveness of group boundaries shape helping behavior

Two experiments exploring the effects of social category membership on real-life helping behavior are reported. In Study 1, intergroup rivalries between soccer fans are used to examine the role of identity in emergency helping. An injured stranger wearing an in-group team shirt is more likely to be helped than when wearing a rival team shirt or an unbranded sports shirt. In Study 2, a more inclusive social categorization is made salient for potential helpers. Helping is extended to those who were previously identified as out-group members but not to those who do not display signs of group membership. Taken together, the studies show the importance of both shared identity between bystander and victim and the inclusiveness of salient identity for increasing the likelihood of emergency intervention.