Abstract
Cross-sectional studies suggest local ecological knowledge (LEK) helps humans adapt to the environment. Among the forms of LEK, adult knowledge of wild plants has been associated with better child and adult health. We assess if the concurrent links between LEK and health last and hypothesize that LEK will yield modest delayed benefits when societies face large socioeconomic and environmental changes. We use a panel (2002-2010) from Tsimane’, an Indigenous Amazonian society (Bolivia). All adults (~440) and children (~300) measured at baseline (2003) in 13 villages were followed yearly during 2004-2010 to estimate associations between (a) baseline adult knowledge and skill about uses of wild plants and (b) subsequent (2004-2010) anthropometric markers of nutritional status of themselves and the children (2y≤age≤10y) in their household at baseline. Among children, HAZ, BMI, and sum of four skinfolds were measured; among adults, BMI, sum of four skinfolds, and body fat with bioelectrical impedance were measured. Some skills loss lowered the likelihood of severe childhood stunting (HAZ<-3) for girls by a large amount; the complete loss of these skills would increase the share of severely stunted girls from 5% to 13%-20%. These are big numbers. The effects of LEK on anthropometric indicators of children or adults were generally small. For example, if all adults in a household lost all botanical knowledge, children’s and women’s BMI would decrease by 3% and 11%, respectively. We invoke large socioeconomic and environmental changes for the finding that LEK does not protect health in full and for the modest effect sizes.