A new self-report instrument, the Children's Object-Spatial Imagery and Verbal Questionnaire (C-OSIVQ), was designed to assess cognitive styles in younger populations (8-17 years old). The questionnaire was based on the previously developed adult version of the Object-Spatial Imagery and Verbal Questionnaire (OSIVQ; Blazhenkova & Kozhevnikov, 2009), and includes three scales assessing object, spatial, and verbal cognitive styles. The C-OSIVQ was validated on a large sample consisting of 267 children and 83 college students. It demonstrated high internal reliability, predictive, and ecological validity in both children and adults. Following the design and validation of the C-OSIVQ, the development of object, spatial, and verbal cognitive styles and their corresponding abilities was examined across a wide range of ages (8-60 years old). The development of styles and abilities were strongly correlated across age groups, indicating that the trajectory of cognitive style development closely resembles the developmental trajectory of abilities; however, the development of cognitive style is more gradual and smooth.