Previous studies with adult human participants revealed that motor activities can influence mental rotation of body parts and abstract shapes. In this study, we investigated the influence of a rotational hand movement on mental rotation performance from a developmental perspective. Children at the age of 5, 8, and 11 years and adults performed a mental rotation task while simultaneously rotating their hand (guided by a handle). The direction of the manual rotation was either compatible or incompatible with the direction of the mental rotation. Response times increased with increasing stimulus orientation angles, indicating that participants of all age groups used mental rotation to perform the task. A differential effect of the compatibility of manual rotation and mental rotation was found for 5-year-olds and 8-year-olds, but not for 11-year-olds and adults. The results of this study suggest that the ability to dissociate motor from visual cognitive processes increases with age. AbstractPrevious studies with adult human participants revealed that motor activities can influence

This study provides an overview of homicide clearance in four West European countries: Finland, the Netherlands, Sweden and Switzerland. Using data from the European Homicide Monitor, employing similar definitions and uniform coding schemes, this study allowed for unique crosscountry comparisons in factors influencing differences in homicide clearance rates. Findings based on homicides occurring in the period 2009-14 revealed overall low homicide rates in all countries, with a wide variety in homicide clearance rates, ranging from 77 percent in the Netherlands to 98 percent in Finland. Results further showed that both event-based as well as victim-based characteristics significantly influenced the likelihood of homicide clearance, suggesting that homicide clearance rates can, for a large part, be attributed to the prevalent types of homicide in each of these European countries.

Objectives This study provides a Finnish replication of a recent Swiss experiment (Walser and Killias: J Exp Criminol 8:17-28, 2012) on the supervision mode effects in computerized delinquency surveys in schools. This study supplements the Swiss study by using individual level randomization and two additional outcome variables: meta-questions of response integrity and incidence-counting heuristics. Methods A total of 924 ninth grade students (15-16 years old) in southern Finland were randomly assigned (at the level of individuals) to supervision either by their teachers or by an external research assistant. Students then responded to an online self-report delinquency survey. Chi-square and t tests were used to compare prevalence levels and means. Results In both last year and lifetime recall periods, only one offence type (unspecified theft) showed significantly different outcomes, with external supervision yielding a higher prevalence figure. For other offences, no supervision effects were found. When females and males were separately examined, limited evidence of gender-specific supervision effects emerged. Thus, females appear to report more thefts in external supervision while males report more violence in teacher supervision. No statistically significant supervision effects were found in questions probing response integrity and counting heuristics. Conclusion Using teacher supervision in online self-report delinquency surveys does not appear to compromise the validity of the survey results. The findings thus largely corroborate the results of the earlier Swiss test. How supervision condition interacts with respondent characteristics apart from gender calls for further scrutiny.

Objectives This study tests whether juveniles' responses on sensitive topics such as selfreported delinquency, victimization, and substance use are comparable when teachers versus external persons supervise students while filling out online questionnaires. Methods Eighty classes with 1,197 students (9th grade) in eastern Switzerland were randomly assigned (at the class level) to supervision either by their teacher or by an external person (i.e., researcher). Students filled out online questionnaires about selfreported delinquency, victimization, and substance use in the classroom while being supervised either by their teacher or by an external person. Prevalence rates were compared using Chi-square tests. Results Only three out of 57 comparisons show significantly different outcomes. Whenever differences are found, and contrary to our expectation, sensitive experiences are more often admitted when students are supervised by their teacher. Effect sizes do not exceed 0.6, and are thus all below the limit of a small effect. Conclusions Using online questionnaires with teachers as supervisors may not affect validity while making surveys less expensive and intrusive.

This study examines homicide trends in seven European countries – Denmark, Estonia, Finland, the Netherlands, Scotland, Sweden and Switzerland – all of which manifested a substantial drop in homicide mortality between 1990 and 2016. By using data from the European Homicide Monitor, a coding scheme created to enable cross-country comparisons, combined with the national cause-of-death statistics, we explore generality versus specificity of the homicide drop. We examine changes in the demographic structure of victims and offenders and disaggregate homicides by different subtypes of lethal incidents, such as family-related homicides referring to conflicts between family members, and criminal milieu homicides occurring in the context of robberies, gang-related conflicts or organised crime. Results point to the generality of the drop: in most of the countries studied, the declining trend included all homicide types. The overall decline in homicide mortality was driven mostly by the decline in male victimisation and offending. In most of the countries, the gender distribution of victims and offenders changed only slightly during the study period, whereas the development of the distribution of homicide types manifested greater diversity. Our findings illustrate the benefits of disaggregated analyses in comparative homicide research.