Is memory enhanced by the context or survival threats? A quantitative and qualitative review on the survival processing paradigm

Consistent with an evolutionary perspective, memory may be enhanced when people are in precarious situations. Particularly, a survival processing effect (SPE) has been found whereby people have better memory for a list of items when the items are rated for their relevance in a grassland context that contains survival threats including predators, and the lack of food and water. In this article, we systematically review research that investigated the SPE to disentangle the contextual effects (e.g., grassland) from survival effects (e.g., presence of predators) on memory. A total of 56 articles (106 experiments) that reported findings relating to the SPE before January 2016 were identified and reviewed. Ten experiments assessed the contextual effect and 5 experiments assessed survival effects. Meta-analysis showed that both contextual and survival effects made medium contributions to improved memory, with survival effect having a greater overall effect compared to contextual effect. Based on a further qualitative review on the scenarios used in the experiments, we concluded that grassland contexts per se may have a weaker effect relative to the presence of survival threat in generating mnemonic advantage. The remaining articles consist of experiments that did not examine contextual or survival effects specifically. These set of findings support the notion that the improved memory for SPE largely stems from survival threat because of the lack of survival threat in the control conditions.