Search

The question why some individuals are more intelligent than others is one of the most important questions of the last 100 years in psychology. This study set out to investigate why individuals are better in matrix reasoning as one of the most prominent proxies of intelligence. One well-replicated finding is that matrix-reasoning items with multiple rules are harder to solve than items with a single rule. Notably, it is assumed that the individual working memory capacity (WMC) plays a crucial role in the processing of items with multiple rules. However, it is still an ongoing question why WMC is facilitating the processing of these items. In this work, we investigated possible roles of WMC in matrix-reasoning items with multiple rules. In doing so, we experimentally manipulated certain processes in matrix reasoning which are suggested in the literature to be more demanded in items with multiple rules. In addition, we observed the impact of WMC on these processes from a functional perspective. That is to say, we defined WMC not as an overall resource, but based on the WMC-literature, we examined which aspect of WMC could be required for the respective processes in matrix reasoning. The first study investigated whether storing partial solutions is required in matrix-reasoning and whether individual storage capacity as one aspect of WMC facilitates the storing of partial solutions. The second study can be regarded as a preliminary study for the third study, which quantified the influence of filtering as a further aspect of WMC on matrix-reasoning. The third study investigated whether selective encoding demands are present in multiple-rule items by means of both behavioral and eye movement analyses. We also observed whether individual filtering ability facilitates selective encoding in matrix reasoning. In addition, we observed whether goal management demands are present in multiple-rule items and whether individual storage and processing as another aspect of WMC is related to goal management. Results of all studies revealed that neither storing partial solutions nor goal management were required in multiple rule items, nor that these demands were associated with the aspects of WMC assessed in the respective studies. In contrast, results indicate that higher difficulties in multiple-rule items were mainly due to higher demands on selective encoding and more importantly, filtering facilitated processing of items with these demands. The results of the present study entail important implications for both matrix-reasoning processing and intelligence but also for our understanding of the involvement of WMC in intelligence.