Dogs as potential models for human cognitive change, and the benefits to dogs from what we have learned about humans: Although rats and mice are more commonly used, the domestic dog may be a better model for complex genetic traits such as those involving behavioral disorders, including brain aging. The dog has several important advantages over rodents as a model for complex behaviors, among which is the shared evolutionary history of dogs and humans emphasized here. In addition, the enthusiasm and close cooperation of dog owners and breeders facilitate an ongoing interest in canine genetics within the dog community and provide access to needed samples. Finally, breeds were developed through selection for specific types of tasks or work and most extant breeds are less than 150 years old, further reducing heterogeneity.