A new research paper has made the strange claim that female genital mutilation (FGM) can have an evolutionary benefit in societies where most women are subjected to the practice. FGM involves altering or injuring the female genitalia for non-medical reasons, and is internationally recognised as a human rights violation. Given that the new paper even starts by describing the harmful physical and psychological effects of the practice, how could the researchers claim FGM confers some sort of benefit in some cases?
The answer is supposedly tied up in the perceived social status of women who have and haven’t been cut in societies where FGM is the norm. This is typically in some or all ethnic groups in countries in northern Africa and the Middle East and in some communities elsewhere. The idea is that when most women in a society are subjected to FGM, those women will be more likely to marry and have children, and so pass on their genes. Conversely, in societies where most women don’t undergo FGM, it becomes a disadvantage for those who do. The evolutionary benefit goes to those women who follow the norm.
But we should be very careful about drawing such bold conclusions from what is actually very limited evidence, particularly when it could have a damaging effect on the international efforts to eliminate FGM.
The new paper, published in Nature Ecology & Evolution, is based on an analysis of data from the Demographic and Health Surveys, which are standard questionnaire surveys undertaken in low and middle-income countries. The answers to the questions on FGM help monitor differences in the prevalence of FGM among women and their daughters by age, region of the country, ethnic group, educational level and religion and between urban and rural areas.
The researchers chose to study five countries in which there are different ethnic groups that have a high and low prevalence of FGM: Burkina Faso, Ivory Coast, Mali, Nigeria and Senegal. These are all in West Africa where the the less severe Type 1 and Type 2 forms of FGM are typically practised. These involve removing part or all of the clitoris or inner labia, but not the narrowing of the vaginal opening by sewing up the outer labia.
The data confirmed that FGM in these areas is what is known as a frequency-dependent behaviour. In other words, girls were more likely to be cut when their mothers were from ethnic groups with a high prevalence of FGM. This idea is already generally accepted, but the researchers also used the data to test a more controversial theory, that this frequency-dependent FGM is associated with evolutionary benefits.