Friendship Quality Scale (FQS)

The Leiden Consortium on Individual Development (L-CID) study was founded by Marinus van IJzendoorn, Eveline Crone, Marian Bakermans-Kranenburg and Rutger Engels in 2013. It was developed as one of four work packages of the overarching Consortium on Individual Development (CID). The L-CID study is a large-scale longitudinal intervention study in which 500 families with same-sex twins are followed over a six year period. L-CID has a cohort-sequential design with two cohorts: an early childhood cohort (ECC), aged 3-4 at wave 1, and a middle childhood cohort (MCC), aged 7-8 at wave 1. Annual assessments consist of alternating lab- or home visits during which behavioral and neurobiological data are collected. The collected data allow, among others, for testing which child characteristics shape the effect of (manipulated) environmental factors. The aim of L-CID is twofold: 1. To investigate the development of social competence and behavioral control in children between 3 and 14 years old; 2. To dissect the reason why not all children are equally responsive to variations in the social environment.

莱顿个体发展研究联盟（Leiden Consortium on Individual Development, L-CID）项目由Marinus van IJzendoorn、Eveline Crone、Marian Bakermans-Kranenburg与Rutger Engels于2013年发起创立。该项目作为综合性个体发展联盟（Consortium on Individual Development, CID）的四大工作包之一开发建设。L-CID是一项大规模纵向干预研究，将对500户拥有同性别双胞胎的家庭开展为期六年的追踪调研。该研究采用队列序列研究设计，包含两个队列：首波调查时年龄为3-4岁的幼儿队列（early childhood cohort, ECC），以及首波调查时年龄为7-8岁的学龄中期队列（middle childhood cohort, MCC）。年度评估采用交替开展的实验室与家庭访问模式，在此过程中收集行为学与神经生物学数据。所采集的数据可用于检验哪些儿童特征会调控经操控的环境因素的影响效应，此为其应用场景之一。L-CID的研究目标兼具双重性：其一，探究3至14岁儿童的社会能力与行为控制发展轨迹；其二，剖析为何并非所有儿童对社会环境变化的响应程度均一致。