Sequent Calculi and Decision Procedures for Weak Modal Systems

We investigate sequent calculi for the weak modal (propositional) system reduced to the equivalence rule and extensions of it up to the full Kripke system containing monotonicity, conjunction and necessitation rules. The calculi have cut elimination and we concentrate on the inversion of rules to give in each case an effective procedure which for every sequent either furnishes a proof or a finite countermodel of it. Applications to the cardinality of countermodels, the inversion of rules and the derivability of Löb rules are given.     

The Observer Video-Pro: New software for the collection, management, and presentation of time-structured data from videotapes and digital media files

The Observer Video-Pro is a system for collecting, managing, analyzing, and presenting observational data. It integrates The Observer software with time code and multimedia hardware components. It extends the functionality of a conventional real-time event recording program in various ways. Observational data can be collected, reviewed, and edited with synchronized display of the corresponding video images. For optimal visual feedback during coding, one can display the video image in a window on the computer screen. Video playback from either a VCR or a digital media file can be controlled by the computer, allowing software-controlled jog, shuttle, and search functions. Besides a wide range of VCRs, The Observer Video-Pro supports all major digital video file formats. The software allows the user to summarize research findings in numerical, graphical, or multimedia format. One can create a time-event plot for a quick glance at the temporal structure of the observed process, or run specific analysis procedures and generate reports with statistics. An Event Summary function is available for exploratory and qualitative analysis. Video material can be summarized in a Video Play List, which allows on-screen summary presentations or the creation of highlight compilations on tape, CD, or other media. Video images can be captured and saved as disk files, for use as illustrations in documents, slides for presentations, and so forth. In this paper we describe the design and operation of the system, illustrated with a case study from research on Repetitive Strain Injury (RSI).     

Perceptions of the Targets and Sources of COVID-19 Threat are Structured by Group Memberships and Responses are Influenced by Identification with Humankind

The purpose of this study was to investigate which social groups are perceived as a threat target and which are perceived as a threat source during the COVID-19 outbreak. In a German sample (N = 1454) we examined perceptions of social groups ranging from those that are psychologically close and smaller (family, friends, neighbors) to those that are more distal and larger (people living in Germany, humankind). We hypothesized that psychologically closer groups would be perceived as less affected by COVID-19 as well as less threatening than more psychologically distal groups. Based on social identity theorizing, we also hypothesized that stronger identification with humankind would change these patterns. Furthermore, we explored how these threat perceptions relate to adherence to COVID-19 health guidelines. In line with our hypotheses, latent random-slope modelling revealed that psychologically distal and larger groups were perceived as more affected by COVID-19 and as more threatening than psychologically closer and smaller groups. Including identification with humankind as a predictor into the threat target model resulted in a steeper increase in threat target perception patterns, whereas identification with humankind did not predict differences in threat source perceptions. Additionally, an increase in threat source perceptions across social groups was associated with more adherence to health guidelines, whereas an increase in threat target perceptions was not. We fully replicated these findings in a subgroup from the original sample (N = 989) four weeks later. We argue that societal recovery from this and other crises will be supported by an inclusive approach informed by a sense of our common identity as human beings.     

Early language outcomes in Argentinean toddlers: Associations with home literacy,screen exposure and joint media engagement

This study aimed to analyse the contribution of mothers' home literacy beliefs and practices and the quantity and quality of screen media exposure on Argentinean toddler's language. In addition, we considered parent–child joint engagement, as well as adult scaffolding behaviours during the use of electronic devices. A total of 465 mothers of 18–36 months old children completed an online survey including: the MacArthur Bates CDI, home literacy, screen exposure, joint engagement and scaffolding questionnaires. We observed positive effects of literacy beliefs, PC times and verbal scaffolding on language outcomes. TV exposure contributed negatively to vocabulary and, along with educational content, to sentence use. Shared reading and screen media experiences can be an opportunity for language stimulation, provided there is dialogue and joint engagement. Passive screen exposure and inadequate content may be detrimental for toddlers' language outcomes, probably by displacement of socially significant interactions.     

Cooperative responding in rats: II. Performance on fixed-ratio schedules of mutual reinforcement

Coordinated responses of 5 dyads of rats were investigated under fixed-ratio (FR) schedules of mutual water reinforcement. Coordinated responding was defined as 2 consecutive lever-presses, 1 from each of 2 rats, occurring <.5 s apart. In the FR schedules, each coordinated episode was defined as 1 response in the FR sequence. The size of FR schedules was parametrically manipulated assuming the values of FR 1, 6, 12, 18, 24, 30, 50, and 9, in this order. Each FR remained in effect until responding reached stability. Under all conditions, pairs of rats received access to water simultaneously (mutual reinforcement). Rates and proportions of coordinated responding showed a bitonic inverted U-shaped function of ratio size. Postreinforcement pauses increased systematically as the interreinforcement interval increased. Local rates and proportions increased as a function of response location within ratios. Results of a control condition with relaxed temporal constraints for mutual reinforcement showed decreases in rates and proportion of coordinated responses, suggesting that the coordinated responses were controlled by the mutual reinforcement contingencies. The present experiment showed that coordinated responding is quantitatively affected by 3 properties of FR schedules: response requirement, reinforcement rates, and proximity to reinforcement.     

The effects of explicit “Not Present” and “Don't Know” response options on identification decisions in computer-administered lineups

Eyewitness researchers recommend that “not present” and “don't know” response options should be presented with police lineups. Although it is important that witnesses—most of whom are unlikely to be familiar with the identification task—are fully cognizant of all response options available to them, an understanding of how explicit non-identification options affect performance is lacking. Across four experiments, including 3,633 participants and 8 different stimulus sets, we tested the effects of including non-identification options in computer-administered lineups. When explicit non-identification options were presented, target-present and -absent choosing decreased. This decrease in choosing was characterized by a shift from filler identifications to lineup rejections. ROC analyses revealed that there was no overall difference in discriminability between guilty and innocent suspects depending on response option condition. On balance, the findings suggest that, in addition to informing witnesses about acceptable responses, displaying non-identification response options does not undermine identification performance.     

Pygmalion in the genes? On the potentially negative impacts of polygenic scores for educational attainment

Social Psychology of Education - Polygenic scores for educational attainment and related variables, such as IQ and “mathematical ability” are now readily available via...