BackgroundIntervention programs with the aim of enhancing parenting quality have been found to be differentially effective in decreasing negative child outcomes such as externalizing behavioral problems, resulting in modest overall effect sizes. Here we present the protocol for a randomized controlled trial to examine the efficacy of the Video-feedback Intervention to promote Positive Parenting and Sensitive Discipline for Twin Families (VIPP-Twins) on parenting quality and children’s behavioral control and social competence. In addition, we aim to test the differential susceptibility theory; we examine differential efficacy of the intervention based on genetic make-up or temperament for both parents and children. Lastly, we explore neurobiological mechanisms underlying intervention effects on children’s developmental outcomes.Methods/designThe original VIPP-SD was adapted for use in families with twins. The VIPP-Twins consists of five biweekly sessions in which the families are visited at home, parent-child interactions are videotaped and parents receive positive feedback on selected video fragments. Families (N = 225) with a same sex twin (mean age = 3.6 years) were recruited to participate in the study. The study consists of four assessments. After two baseline assessments in year 1 and year 2, a random 40 % of the sample will receive the VIPP-Twins program. The first post-test assessment will be carried out one month after the intervention and there will be a long term follow-up assessment two years after the intervention. Measures include observational assessments of parenting and children’s social competence and behavioral control, and neurobiological assessments (i.e., hormonal functioning and neural (re-)activity).DiscussionResults of the study will provide insights in the efficacy of the VIPP-Twins and reveal moderators and mediators of program efficacy. Overall the randomized controlled trial is an experimental test of the differential susceptibility theory.Trial registrationDutch Trial Register: NTR5312; Date registered: July 20, 2015.Electronic supplementary materialThe online version of this article (doi:10.1186/s40359-016-0139-y) contains supplementary material, which is available to authorized users.

In this study we examined prosocial compensating behavior towards socially excluded ingroup and outgroup members by using a 'Prosocial Cyberball Game' in 9-17 year old Dutch adolescents (N = 133). Results showed that adolescents compensated for the social exclusion of an unknown peer in a virtual ball tossing game, by tossing the ball more often to that player in compensation conditions compared to the fair play condition. The proportion of tosses towards the excluded player did not significantly differ as a function of the group status of that player. Although compensating behavior towards ingroup versus outgroup members did not differ, the underlying motivation for this behavior may vary. More empathic concern was associated with more prosocial tosses towards an ingroup member, while more self-reported bullying behavior was associated with less compensating behavior in the outgroup condition. These findings may have practical implications for programs intending to change bystander behavior in bullying situations.

Background Primary aim of the current randomized controlled trial was to test the effectiveness of the parenting intervention ‘Video-feedback to promote Positive Parenting and Sensitive Discipline’ (VIPP-SD) in a sample of parents of preschool-aged twins, as well as differential susceptibility to intervention efforts, that is, whether more temperamentally reactive parents would profit more from the VIPP-SD than parents with lower reactivity. Methods The sample consisted of 202 families with same-sex twins [N = 404 children, mean age 45 months (SD = 6.81)]. Randomization was done at the family level in a 2:3 ratio, with 83 families (41%) randomized to the VIPP-SD group, and 119 families (59%) to the control group. After two pre-tests in year 1 and year 2 of the study, the VIPP-SD was implemented in the third year, with a post-test assessment 1 month after the five intervention sessions. Parental sensitivity was observed during structured play in which parent and child copied a drawing together in a computerized Etch-A-Sketch paradigm. Parental limit-setting was observed in a ‘don’t touch’ task in which the parent required from the child to abstain from playing with attractive toys. Parents interacted with each of their twins in separate sessions. Results The VIPP-SD intervention had a positive impact on the level of parents’ positive limit-setting in interaction with their preschool twins, and this positive effect was most pronounced when the parents completed at least five intervention sessions. However, the intervention did not enhance parental sensitivity during structured play. Parents with higher reactivity were not more open to the impact of the intervention, thus for this temperamental marker differential susceptibility in adults was not supported. Conclusions The current study is unique in targeting families with twin preschoolers, providing proof of principle that coaching parents with video-feedback promotes parental sensitive limit-setting to both children. It remains to be seen whether this finding can be replicated in families with non-twin siblings, or other parental susceptibility markers. Trial registration Trial NL5172 (NTR5312), 2015-07-20.

We examined the relative contribution of genetic, shared environmental and non-shared environmental factors to the covariance between parental sensitivity and limit-setting observed twice in a longitudinal study using a child-based twin design. Parental sensitivity and parental limit-setting were observed in 236 parents with each of their same-sex toddler twin children (M age = 3.8 years; 58% monozygotic). Bivariate behavioral genetic models indicated substantial effects of similar shared environmental factors on parental sensitivity and limitsetting and on the overlap within sensitivity and limit-setting across 1 year. Moderate child-driven genetic effects were found for parental limit-setting in year 1 and across 1 year. Genetic child factors contributing to explaining the variance in limit-setting over time were the same, whereas shared environmental factors showed some overlap. The authors thank the families for their participation in the longitudinal twin study "Samen Uniek" and the people involved in the data collection and coding of the video's. The Leiden Consortium on Individual Development (L-CID) is funded through the Gravitation program of the Dutch Ministry of Education, Culture, and Science and the Netherlands Organization for Scientific Research (NWO grant number 024.001.003).

Parenting interventions have proven to be effective in enhancing positive parenting behavior and child outcomes. However, the neurocognitive mechanisms explaining the efficacy remain largely unknown. We tested effects of the Video-feedback Intervention to promote Positive Parenting and Sensitive Discipline (VIPP-SD) on mothers' neural processing of child faces. Our primary focus was on the N170 and the secondary focus on the LPP. We expected the intervention to enhance the amplitudes of both ERP components in response to emotional compared to neutral faces. A total of 66 mothers visited the lab for two identical sessions separated by 4.28 months (SD = 0.86) during which a random 33% of the mothers received the VIPP-SD. During both pre-and post-intervention sessions, mothers' electroencephalographic (EEG) activity in response to photographs of children's neutral, happy and angry facial expressions were acquired. In contrast to our expectations, we found smaller (less negative) N170 amplitudes at post-test in the intervention group. There was no intervention effect on the LPP, although overall LPP amplitudes were more positive for neutral and angry compared to happy faces. Our study shows that the N170 is affected by the VIPP-SD, suggesting that the intervention promotes efficient, less effortful face processing.