From school lessons to life lessons: School knowledge, life knowledge and their relation to biographical experiences

Crystallized intelligence (gc) is typically defined as the breadth and depth of a person's knowledge and skills within a culture. Contemporary assessments of gc in adults often focus on school-based knowledge acquired through formal education. To broaden this scope, we developed a gc measure that captures life knowledge acquired through biographical experiences outside formal schooling. A sample of 348 adults completed items assessing school knowledge and newly developed items targeting life knowledge, tailored to specific biographical experiences, covering five areas: humanities, natural sciences, life sciences, arts, and social sciences. Besides the knowledge items, participants also answered questions about the associated biographical experiences. Latent factors for both knowledge item sets correlated perfectly with each other. Nonetheless, correlations between biographical experiences and corresponding life knowledge items were slightly stronger than correlations between biographical items and non-corresponding life or school knowledge items. We discuss the often-neglected relevance of the source of knowledge acquisition and biographical learning opportunities, and consider their implications for the psychometric modeling of gc. • Assessment of Crystallized Intelligence (gc) can be broadened beyond traditional school-based knowledge by compiling items that capture life knowledge which can be acquired through biographical experiences. • Latent factors for the life knowledge and school knowledge correlated perfectly, supporting a unified concept of gc regardless of the acquisition context. • Correlations between self-reported biographical experiences and their corresponding life knowledge items were stronger than with non-corresponding knowledge items when controlling for general knowledge, suggesting biographical experiences are an important source of knowledge acquisition.