Ingredients of complexity in fluid intelligence

Abstract

Two studies were carried out to investigate the relationship between performances on two experimental tasks—Triplet Numbers and Swaps—and measures of fluid intelligence (Gf) and short-term memory (SAR). For each of these tasks four different versions of increasing complexity were constructed by varying the number of rules or mental steps required for their solution. Both tasks in the first study, and Swaps in the second study, were given twice with the instruction to work as quickly and as accurately as possible. Changes in speed/accuracy emphasis produced reliable differences in performance on the Triplet Numbers test in the first study only. As expected, increasing task complexity resulted in lower accuracy and slower responding. Regarding the relationship between the experimental tasks and intelligence factors, Gf and SAR, the most consistent and strongest association was between the accuracy measures of these tasks and Gf, although in all cases the relationship between both factors and speed scores were statistically significant. Importantly, the most consistent and strongest interaction between task complexity and Gf was obtained using accuracy measures from the experimental tasks. Other interactions with task complexity were weak. In general, as the task becomes more complex, its correlation with measures of intelligence tends to increase.