Many species habitually live in groups, which has both costs and benefits to the individual. As living in groups is theorised to be an anti-predator strategy, hunting by humans could impact group size. Using group-living diurnal primates as a model species group, this meta-analysis investigates whether human hunting affects group sizes. The file Primate group size and hunting.xlsx contains data from the studies identified by a systematic review, and a key identifying the variables. The .html file contains a description of each of the dataset, code used to analyse the data, and the analysis outputs. The file Rejected papers at full text.xlsx contains information about the reason for rejection at the full text stage.