Bimodality in the Berlin model of intelligence structure (BIS): A replication study

The bimodal structure of intelligence as proposed in the ‘Berlin model of intelligence structure’ (BIS) (Jäger, 1982) and measured by the BIS-4 test was analysed in a sample of 182 subjects. According to this theory two modalities characterize the structure, both emerging from results in 45 mental tasks and containing a total of seven components: Operations (processing speed, memory, creativity, processing capacity), and contents (verbal, numerical, figurai ability), as well as the general factor (g). Exploratory analysis following Jägerʹs approach revealed the existence of four operations and three contents. The simultaneous examination of the bimodality in the structure of the BIS was performed by means of confirmatory factor analysis. The theoretically proposed bimodal model (four operations and three contents) was compared with a unimodal model involving seven correlated factors of the same level and with other alternative unimodal models. In these analyses a slight superiority of operations over contents was observed. The reasons for our preference of the bimodal BIS structure compared to other unimodal solutions are clarified and the role of operations and contents in the construct of intelligence is discussed.