Primary vs. secondary knowledge contents in reasoning: Motivated and efficient vs. overburdened

Primary knowledge is the knowledge for which our cognitive architecture has evolved so that we acquire it quickly and effortlessly. We are intrinsically motivated to process it. Secondary knowledge is the knowledge for which our cognitive architecture has not had enough time to evolve: it requires time, cognitive resources and is hardly motivating. This study proposed to test these evolutionary characteristics using the experimental paradigm of logical reasoning. We conducted five experiments (n = 720) varying (i) the content of syllogisms (primary or secondary knowledge), (ii) the presentation order of the knowledge types, (iii) the added extrinsic cognitive load, and (iv) the type of syllogism. Results showed that primary knowledge increased performance, emotional and cognitive investment and decreased perceived cognitive load. Second, presenting primary knowledge first would encourage participants to be motivated throughout the task, while presenting secondary knowledge first would undermine their motivation. Third, secondary knowledge seemed to lead to a feeling of conflict that consumed cognitive resources. All together, these results suggested that primary knowledge should be taken into account and not left aside because it is something “already learned”.