How scientists perceive the evolutionary origin of human traits: results of a survey study

Various hypotheses have been proposed for why the traits distinguishing humans from other primates originally evolved, and any given trait may have been explained both as an adaptation to different environments and as a result of demands from social organization or sexual selection. To find out how popular the different explanations are among scientists, we carried out an online survey among authors of recent scientific papers in journals covering relevant fields of science (palaeoanthropology, palaeontology, ecology, evolution, human biology). Some of the hypotheses were clearly more popular among the 1266 respondents than others, but none was universally accepted or rejected. Even the most popular of the hypotheses were assessed “very likely” by <50 % of the respondents, but many traits had 1–3 hypotheses that were found at least moderately likely by >70 % of the respondents. An ordination of the hypotheses identified two strong gradients. Along one gradient, the hypotheses were...