This article reviews research that has shown consistency in fear responses in ruminant livestock. The authors also provide evidence that there is a genetic basis for fear responsiveness, and discuss the problems with genetic evaluation and selection. Some of the problems include the absence of validation in experimental designs, the complexity of fear-related responses, and the inconsistency of fear-related responses due to the interaction between genetic and environmental factors. The following topics are discussed: the possible welfare consequences of selection programs currently used, the possibility of including fear criteria in selection programs, and recent evidence on how genes control fearfulness. The ability to select animals that easily adapt and are less fearful has potential to improve their welfare.