Confirmation bias leads to overestimation of losses of woody plant foliage to insect herbivores in tropical regions.

ABSTRACT: Confirmation bias, i.e., the tendency of humans to seek out evidence in a manner that confirms their hypotheses, is almost overlooked in ecological studies. For decades, insect herbivory was commonly accepted to be highest in tropical regions. By comparing the data collected blindly (when the observer was not aware of the research hypothesis being tested) with the results of non-blind studies (when the observer knew what results could be expected), we tested the hypothesis that the records made in the tropics could have overestimated community-wide losses of plant foliage to insects due to the confirmation bias. The average loss of leaf area of woody plants to defoliating insects in Brazil, when measured by a blind method (1.11%), was significantly lower than the loss measured in non-blind

SUBMITTER: Kozlov MV 

PROVIDER: S-EPMC4277485 | biostudies-literature | 2014

REPOSITORIES: biostudies-literature