And although APOE4 is a bigger risk factor for Alzheimer’s than is APOE3, and Alzheimer’s involves cognitive decline, among infected Tsimane Amazon-Indians, APOE4 is associated with better cognition than APOE3 (Trumble et al., 2017; see also van Exel et al., 2017; Zhao et al., 2020). This evidence concerns the gene APOE and Mental deterioration.