Stereotypic behaviours (SBs) are commonly grouped together under the implicit assumption that they are homogeneous. However, little research has investigated whether this is valid. Thus, this thesis investigated whether various SB forms are homogeneous in Carnivora, using the American mink (Neovison vison) as a model. To assess homogeneity, I employed statistical analyses: I explored whether the time-budgets of different SB forms were correlated with each other, and whether they were more likely to co-occur within bouts of SB more so than expected by chance. I also investigated whether different SB forms showed similar relationships with perseverative responding under test. Although no relationships were found between SB form and perseveration, other results showed that some SBs positively correlated with each other, and that some SB forms co-occurred with each other in bouts. Overall, these findings suggest that SBs are heterogeneous and emphasize the need to collapse SBs into meaningful subcategories instead.