Why Africa has a high HIV/AIDS infection rate

Note: The use of racial/gender references does not imply bias or discrimination. This blog post is just a dispassionate interrogation of scientific data.

A map of the prevalence of HIV/AIDS in the world:

I’ve been browsing through Nicholas Christakis et al’s book entitled Connected: The Surprising Power Of Our Social Networks, and I think I now understand why Africa has a higher HIV/AIDS infection rate than Western Europe; it all boils down to differences between the mating habits of Caucasians and Native Africans.

According to Messr. Christakis, whites with many sexual partners tend to have sex with other whites with lots of partners, and; whites with few partners have sex with whites with few partners. Whereas, blacks with many partners have sex with blacks with BOTH few and many partners. [1]

[What does this mean: This could mean that mating relations in white people follow the homophily principle; ‘like people mating with like people’, and mating relationships in black people follow it to a lesser extent. I would be interested in finding out why…]

Hence, STDs, like HIV/AIDS are held in the “core” of white sexual networks. Whereas, in active black partners, they tend to spread to the periphery of the sexual network, as shown by the blue and purple nodes in the diagrams below.

In the sexual networks below, a line represents a sexual relationship between two people. The central nodes represent the more embedded people; the people with the most overlapping sexual partners (which correlates with a high HIV/AIDS infection rate) and the peripheral nodes represent the people with fewer overlapping sexual partners:

Network illustrating HIV Infection Rate in White People:

Network illustrating HIV Infection Rate in Black People:

This ‘mating disparity’, among other things, contributes to the differences between the HIV/AIDS infection rates in Sub-Saharan Africa and Western Europe OR among white populations and black populations in the same localities.

Weird stuff!   

[1] Generally, at a global level, people prefer to have intimate relations with people of their own race.