Two behavioral traits, temperament and habituation, were measured in 130 calvesfrom 17 full-sib families which comprise the Canadian Beef Cattle ReferenceHerd. Using variance components, heritability was calculated as 0.36 fortemperament and 0.46 for habituation. Genotyping of 162 microsatellites atapproximately 20 cM intervals allowed the detection of six quantitative traitloci (QTL) for behavior traits on cattle chromosomes 1, 5, 9, 11, 14, 15.