Only a few pieces of the study is visible, because it is under copyright. It is possible to buy it here.
It should be noted that the study indicates that the biparietal diameter (BPD) of the African Child is less than the biparietal diameter of the European child even during pregnancy, in the same week of pregnancy. Thus, this is not because African women have an average pregnancy that is shorter than European women (38/39 weeks in Africa, 39/40 in Asia, 41/42 in Europe).
You understand that this study is central on the question of hybridization between Sapiens and Neanderthal. Indeed, the biparietal diameter of the African Child is adapted to the narrow morphology of the pelvis of the mother, but what happens if the father is European?
The baby can not be delivered so easy if they inherit the father’s head…