Frequent exposure to victimization by peers is related to greater psychological problems. It is often assumed that peer victimization is associated with fewer psychological problems in classrooms where defending victims of bullying is common (i.e., a norm). The few studies testing this claim have been cross-sectional and have produced mixed…

Victimization during school years can have detrimental effects on individuals' adjustment, lasting even into adulthood. In the current study, we examine whether there is an indirect effect of victimization on adult depression and aggression, via sad and angry rumination about past victimization. Participants included 1,319 Finnish individuals…

Youth with greater levels of narcissism face a wide array of difficulties in interactions with others. However, there exists a curious lack of research on their close relationships, such as friendships. In this study, we examined associations between narcissism and friendship features over time. Participants were 261 eighth and ninth graders (112…

The normative, developmental changes in affect-biased attention during the preschool years are largely unknown. To investigate the attention bias for emotional versus neutral faces, an eye-tracking measurement and free viewing of paired pictures of facial expressions (i.e., happy, fearful, sad, or angry faces) and nonface pictures with neutral…

The aim of the present study was to examine the kinds of developmental profiles of arithmetic fluency skills that can be identified across Grades 1-9 (ages 7-16) in a large Finnish sample (n = 2,518). The study also examined whether membership in the developmental profiles could be predicted using a comprehensive set of kindergarten-age factors,…

Effective social support from teachers, peers, and guardians is a key to promoting students' study wellbeing at school. However, little longitudinal research has examined the implications of distinctive combinations of social support for students' study wellbeing. To address this limitation, we measured multiple dimensions of school-related social…

This study examined developmental profiles of reading fluency and reading comprehension in Grades 1 to 9 (ages 7 to 15) in a large Finnish sample (N = 2,518). In addition, early predictors of the profiles were analyzed with respect to kindergarten cognitive skills (phonological awareness, letter knowledge, rapid automized naming [RAN], number…

Complexity is one of the major demands of adolescents' future life as adults. To investigate adolescents' competence development in applying problem-solving strategies in complex environments, we conducted a 2-wave longitudinal study in a sample of Finnish adolescents (11-17 years old; N = 1,959 at Time 1 and N = 1,690 at Time 2, 3 years later).…

Compassion is known to predict prosocial behavior and moral judgments related to harm. Despite the centrality of compassion to social life, factors predicting adulthood compassion are largely unknown. We examined whether qualities of parent-child-relationship, namely, emotional warmth and acceptance, predict offspring compassion decades later in…

Fragmented sleep is common in infancy. Although night awakening is known to decrease with age, in some infants night awakening is more persistent and continues into older ages. However, the influence of fragmented sleep on development is poorly known. In the present study, the longitudinal relationship between fragmented sleep and psychomotor…

Nordic welfare states have been very successful at reducing poverty and inequality among their citizens. However, the presence of a strong social safety net in these countries has not solved the problem of "socioeconomic exclusion", manifesting in such outcomes as chronic unemployment and welfare dependency. In an effort to understand…

Saccade latency is widely used across infant psychology to investigate infants' understanding of events. Interpreting particular latency values requires knowledge of standard saccadic RTs, but there is no consensus as to typical values. This study provides standard estimates of infants' (n = 194, ages 9 to 15 months) saccadic RTs under a range of…

The longitudinal relations of domain-general and numerical skills at ages 6-7 years to 3 cognitive domains of arithmetic learning, namely knowing (written computation), applying (arithmetic word problems), and reasoning (arithmetic reasoning) at age 11, were examined for a representative sample of 378 Finnish children. The results showed that…

Existing gap-year research indicates a number of benefits of a gap-year at the end of school and before university enrollment. Life span theory of control, however, suggests that direct goal investment, rather than delay, at developmental transitions is associated with more adaptive outcomes. Comparing these perspectives, the authors undertook 2…

This study examined whether the degree to which bullying is normative in the classroom would moderate associations between "intra"- (cognitive and affective empathy, self-efficacy beliefs) and "inter"personal (popularity) factors and defending behavior. Participants were 6,708 third- to fifth-grade children (49% boys;…