The US is weird about breastfeeding

There's been so much buzz over Time's breastmilk-sploitation cover photo (milxploitation? boob-sploitation?) that I've decided the cover of my book should be an image of yours truly breastfeeding Jamie Lynne Grumet or some other suitably hot young mom.
Out of all of that though I found one particularly arresting graph that shows just how strange breastfeeding practices are in this country. As you can see, we are distinctly abnormal.

A comparison of age at weaning in the United States and in 64 traditional societies,
reproduced from Stuart-Macadam & Dettwyler (1995)

Eric Michael Johnson dug that up. You can read his parsing of the science here. Thanks to my editor at Rodale, Alex Postman, who brought my attention to this.