Lowes and Nunn test the theory that the transatlantic and Indian Ocean slave trades of the thirteenth to nineteenth centuries prompted a shift towards matrilineal kinship systems throughout sub-Saharan Africa. Controlling for ecological variables commonly thought to affect kinship structure (including ruggedness of terrain, suitability for agriculture, etc.), the authors find a significant correlation between the number of people enslaved from a given ethnic group, and the tendency of that group towards a matrilineal kinship system. Polygyny was also identified as a statistically significant characteristic of communities most impacted by the slave trade.