Future researchers working on collecting normative sample data should consider gathering information on mild cognitive impairment and pre-clinical dementia (as well as other vascular risk factors—for risk of vascular dementia [body mass index, metabolic profile; Tariq and Barber 2018]—and main bio indices such as APOE e4) to aid in determining exactly who should and who should not be included in a representative sample of typical adults. This evidence concerns the gene APOE and dementia.