Quantitative impacts of AM in human genetics have been investigated by focusing on the deviation from the Hardy - Weinberg equilibrium ( HWE ) in trait - associated variants . However , this approach requires large sample sizes , especially when the effect sizes of the associated variants are small . Furthermore , ancestral endogamy ( mating within the limits of a specific social group ) could confound these relationships [ 10][11][12 ] . An alternative approach is to study genetic similarities between partners . This approach revealed the existence of AM in Europeans on anthropometric traits ( height and body mass index ( BMI ) ) , and social and behavioural phenotypes ( educational attainment and alcohol consumption ) [ 13][14][15][16][17 ] . Although partner genotype - phenotype data have been analysed in these studies , it has been relatively challenging to achieve biobank - scale sample sizes in populations of diverse ancestries .