That pesky 4.2 year figure. For many years, Ruth Lawrence has claimed in her book Breastfeeding: A Guide for the Medical Profession, that there is a worldwide average duration for breastfeeding. She writes: “The average time of complete cessation [of breastfeeding] worldwide is 4.2 years.” (Lawrence 1994:312). This 4.2 year figure is widely cited by numerous groups, including La Leche League members, lactation consultants,