Assessing the Quality of the Family Interrelationship Variable in Classificatory Kinship Populations

The family interrelationship variable is widely used to study household structure, child fostering, and intergenerational support. Yet its measurement validity has not been assessed in populations with classificatory kinship systems—prevalent across most of sub‐Saharan Africa—where kinship terminology groups relatives by generation rather than by direct biological link. This study provides the first empirical assessment of this variable in a West African classificatory context. Using genealogical data from the SLAM (Suivi Longitudinal au Mali ‐ Longitudinal survey in Mali) survey in rural Mali, linked at the individual level to the 2009 national census, we compare census‐reported relationships to the household head with genealogically reconstructed ties among the Bwa, who follow a classificatory terminology. The results reveal systematic and directional discrepancies: nephews, nieces, and stepchildren are frequently reported as biological children of the household head. These findings highlight how the imposition of Western nuclear‐family categories in classificatory kinship settings produces nonrandom biases, leading to inflated counts of household head's children and underestimation of extended family ties.