Matching- and nonmatching-to-sample concept learning in rats using olfactory stimuli

Previous research has shown that rats can learn matching-to-sample relations with olfactory stimuli; however, the specific characteristics of this relational control are unclear. In Experiment 1, 6 rats were trained to either match or nonmatch to sample in a modified operant chamber using common household spices as olfactory stimuli. After matching or nonmatching training with 10 exemplars, the contingencies were reversed with five new stimuli such that subjects trained on matching were shifted to nonmatching and vice versa. Following these reversed contingencies, the effects of the original training persisted for many trials with new exemplars. In Experiment 2, 9 rats were trained with matching procedures in an arena that provided for 18 different spatial locations for comparison stimuli. Five subjects were trained with differential reinforcement outcomes and 4 with only one type of reinforcer. Differential outcomes and multiple exemplars facilitated learning, and there was strong evidence for generalization to new stimuli for most rats that acquired several conditional discriminations. Performances with novel samples were generally above chance, but rarely reached the high levels obtained during baseline with well-trained stimulus relations. However, taken together, the data from the two experiments extend previous work, show that rats can learn both match and nonmatch relations with different experimental protocols, and demonstrate generalization to novel sample stimuli.     

Some determinants of remote behavioral history effects in humans

Undergraduates were exposed to a series of reinforcement schedules: first, to a fixed-ratio (FR) schedule in the presence of one stimulus and to a differential-reinforcement-of-low-rate (DRL) schedule in the presence of another (multiple FR DRL training), then to a fixed-interval (FI) schedule in the presence of a third stimulus (FI baseline), next to the FI schedule under the stimuli previously correlated with the FR and DRL schedules (multiple FI FI testing), and, finally, to a single session of the multiple FR DRL schedule again (multiple FR DRL testing). Response rates during the multiple FI FI schedule were higher under the former FR stimulus than under the former DRL stimulus. This effect of remote histories was prolonged when either the number of FI-baseline sessions was small or zero, or the time interval between the multiple FR DRL training and the multiple FI FI testing was short. Response rates under these two stimuli converged with continued exposure to the multiple FI FI schedule in most cases, but quickly differentiated when the schedule returned to the multiple FR DRL.     

On the development and mechanics of delayed matching-to-sample performance

Despite its frequent use to assess effects of environmental and pharmacological variables on short-term memory, little is known about the development of delayed matching-to-sample (DMTS) performance. This study was designed to examine the dimensions and dynamics of DMTS performance development over a long period of exposure to provide a more secure foundation for assessing stability in future research. Six pigeons were exposed to a DMTS task with variable delays for 300 sessions (i.e., 18,000 total trials; 3,600 trials per retention interval). Percent-correct and log-d measures used to quantify the development of conditional stimulus control under the procedure generally and at each of five retention intervals (0, 2, 4, 8 and 16-s) individually revealed that high levels of accuracy developed relatively quickly under the shorter retention intervals, but increases in accuracy under the longer retention intervals sometimes were not observed until 100-150 sessions had passed, with some still increasing at Session 300. Analyses of errors suggested that retention intervals induced biases by shifting control from the sample stimulus to control by position, something that was predicted by observed response biases during initial training. These results suggest that although it may require a great deal of exposure to DMTS prior to obtaining asymptotic steady state, quantification of model parameters may help predict trends when extended exposure is not feasible.     

Criminal thinking patterns, aggression styles, and the psychopathic traits of late high school bullies and bully-victims

This study explored the current psychological characteristics and criminal behavior history of individuals who retrospectively reported being bullies, bully-victims, victims, or controls (i.e. neither victims nor bullies) during their last 2 years of high school. College students (n = 960) completed measures of criminal thinking, aggression, psychopathy, and criminal behavior online. We predicted bullies and bully-victims would demonstrate the highest scores for criminal thinking, proactive aggression, psychopathy, and have the most criminal infractions. Bullies and bully-victims had significantly higher scores on criminal thinking, aggression, psychopathy, and criminal behaviors than victims or controls. Additionally, men were significantly higher in criminal thinking, aggression, psychopathy, and had more criminal acts than women. There were no gender by bully group interactions. Logistic regression analyses differentiated bully-victims from bullies. Bully-victims tended to be male, higher in criminal thinking, and higher in reactive aggression. In addition, bully-victims were distinct from victims, showing higher criminal thinking and higher proactive aggression.     

Getting precise and pragmatic about the assessment of bullying: the development of the California Bullying Victimization Scale

Accurate assessment of bullying is essential to intervention planning and evaluation. Limitations to many currently available self-report measures of bullying victimization include a lack of psychometric information, use of the emotionally laden term "bullying" in definition-first approaches to self-report surveys, and not assessing all components of the definition of bullying (chronicity, intentionality, and imbalance of power) in behavioral-based self-report methods. To address these limitations, we developed the California Bullying Victimization Scale (CBVS), which is a self-report scale that measures the three-part definition of bullying without the use of the term bully. We examined test-retest reliability and the concurrent and predictive validity of the CBVS across students in Grades 5-12 in four central California schools. Concurrent validity was assessed by comparing the CBVS with a common, definition-based bullying victimization measure. Predictive validity was examined through the co-administration of measures of psychological well-being. Analysis by grade and gender are included. Results support the test-retest reliability of the CBVS over a 2-week period. The CBVS was significantly, positively correlated with another bullying assessment and was related in expected directions to measures of well-being. Implications for differentiating peer victimization and bullying victimization via self-report measures are discussed.     

No postnatal maternal effect on male aggressiveness in wild-derived strains of house mice

Male aggressiveness is a complex behavior influenced by a number of genetic and non-genetic factors. Traditionally, the contribution of each of these factors has been established from experiments using artificially selected strains for high/low aggressive phenotypes. However, little is known about the factors underlying aggressive behavior in natural populations. In this study, we assess the influence of genetic background vs. postnatal maternal environment using a set of cross-fostering experiments between two wild-derived inbred strains, displaying high (STRA, derived from Mus musculus domesticus) and low (BUSNA, derived from Mus musculus musculus) levels of aggressiveness. The role of maternal environment was tested in males with the same genetic background (i.e. strain origin) reared under three different conditions: unfostered (weaned by mother), infostered (weaned by an unfamiliar dam from the same strain), and cross-fostered (weaned by a dam from a different strain). All males were tested against non-aggressive opponents from the A/J inbred strain. Resource-holding potential was assessed through body weight gains and territory ownership. The STRA males were shown to be aggressive in both neutral cage and resident-intruder tests. On the contrary, the BUSNA males were less aggressive in all tests. We did not find a significant effect of postnatal maternal environment; however, we detected significant maternal effect on body weight with differences between the strains, fostering type and interactions between these factors. We conclude that the aggressiveness preserved in the two strains has significant genetic component whose genetic basis can be dissected by quantitative trait loci analysis.     

Acceptance of sexual aggression myths in a representative sample of German residents

A representative sample of German residents (N = 5397) was surveyed with the aim of studying their acceptance of contemporary rape myths (RMA), using items from the Acceptance of Modern Myths About Sexual Aggression Scale [AMMSA; Gerger et al., 2007] in relation to demographic variables (e.g., gender, age), intolerant belief systems (e.g., sexism, islamophobia), the ideologies of rightwing authoritarianism (RWA), and social dominance orientation (SDO), as well as gender identification. Age showed a U-shaped relationship with RMA, whereas gender was unrelated to RMA. For men (women), greater identification with their gender was associated with higher (lower) RMA. Substantial correlations of RMA with intolerant belief systems support the idea of a schema of intolerance. Although RWA and SDO were both related to RMA, only RWA explained unique variance beyond the effects of intolerant belief systems. Results are discussed in comparison to prior studies using mainly student samples.     

Multidimensional treatment foster care (MTFC): results from an independent replication

This study examines 24‐months post‐baseline outcomes for thirty‐five Swedish antisocial youths who received either treatment in multidimensional treatment foster care (MTFC) or treatment as usual (TAU). MTFC is a community‐based treatment programme that has been successful in treating chronic juvenile offenders in the USA. This study is the first randomized control study outside the USA. The youth treated in the MTFC programme consistently showed some statistically significant positive treatment effects compared to the youth exposed to TAU. The results suggest that MTFC might be an effective method in treating youth with severe behaviour problems in a Swedish context. The authors conclude that the programme ought to be of great interest for Swedish social services as an alternative to traditional care.     

God and Country: The Partisan Psychology of the Presidency,Religion, and Nation

Overt love of God and country have seemingly been prerequisites to be president in the United States in recent decades, if not always. Indeed, the 2008 presidential race was replete with campaign messages showcasing such perspectives—that Barack Obama and John McCain were religiously faithful and deeply patriotic. Scholarship demonstrates the potential political power of explicit appeals to America and Christianity; however, little research has examined (a) citizens' perceptions of candidates' ties to faith and nation and (b) how these impressions may be related to electoral attitudes and intended vote. We address this gap, measuring both explicit and implicit indicators of the Christian‐ness and American‐ness of Obama and McCain. We expected and found that both explicit and—in a final‐entry regression position—implicit perceptions of these traits related to voters' overall candidate attitudes and intended vote choice and that they were connected significantly more strongly for our sample of self‐described Republicans than Democrats. Results illuminate these partisan differences and raise questions about their implications for U.S. presidential politics in years to come.     

Sex differences in the relation between math performance, spatial skills, and attitudes

Sex differences have been previously found in cognitive and affective predictors of math achievement, including spatial skills and math attitudes. It is important to determine whether there are sex differences not only in the predictors themselves, but also in the nature of their relation to math achievement. The present paper examined spatial skills and math attitudes as predictors of curriculum-based measures of math performance in middle-school students, specifically comparing the patterns of these predictive relations for boys and girls. The results of the current study showed that, despite similar levels of math performance for boys and girls, the significance of particular predictors varied as a function of sex. Specifically, spatial skills predicted math performance in boys, but not in girls. We suggest that sex differences in spatial reasoning in conjunction with the differential involvement of spatial reasoning in math problem solving may lead to later sex differences in math outcomes.