Further research is needed to increase knowledge about such theories. In the decades that scientists have been trying to find the root causes of BIM, many theories were offered which later research proved inaccurate. Bear in mind this important distinction. While most of the conditions that are mentioned in these myths are indeed infant mortality risk factors, they do not define the black risk factor. Their presence contributes to but does not account for all of black infant mortality.
Infant mortality is higher for blacks because so many black adolescents are giving birth.
BIM is high because too many black mothers are single. Their studies showed that the four factors had directionally similar but quantitatively different effects on both categories of birth weight in blacks and whites. In other words, blacks had higher rates than whites for every combination of maternal characteristics. BIM is high because too many black mothers are uneducated. Studies of socioeconomic status and race show that while whites tend to have improved infant mortality rates when socioeconomic status improves, blacks do not.