Siedlecki and Salthouse (2013) have conducted the kind of intelligence research I love to read. In “Using contextual analysis to investigate the nature of spatial memory,” they describe how they had noticed an incidental finding from a previous study that intrigued them and then carefully designed a battery of tests to see if the phenomenon would replicate and withstand several challenges to the original interpretation. It did.
The specific finding is that after accounting for fluid intelligence, spatial memory has no unique relationship with reference markers of verbal memory. This finding is important because it suggests that although it is fine to talk about “memory” as a conceptual category, there may not be an ability called general memory.
The evidence from this paper (and earlier studies) suggests that CHC Theory may need to be amended such that spatial memory and visual memory are distinguished. Furthermore, spatial memory seems to have a special relationship with fluid intelligence, even when fluid intelligence is measured with non-spatial tests.
What l like about this study is that its methodological rigor makes the finding much more persuasive than is the case in most individual differences research. Most studies in this area are from convenience samples and rarely are designed to test highly specific hypotheses.