Origin of the domestic dog or the result of natural introgression as the dog expanded across Eurasia. In 2018, a study found a small amount of dog ancestry in 62% of Eurasian wolf specimens looked at, that hybridization had occurred across a wide number of timescales and not just recently, however in contrast there was almost no admixture detected in the North American specimens. There was introgression of the male dog into the wolf, but also one hybrid detected which was the result of a male wolf crossed with a female dog. Wolves have maintained their phenotype differences from the dog, which indicates low-frequency hybridization.
Dog training punishment are at risk of developing disturbances associated with the learned helplessness disorder. Punishment which is poorly coordinated with identifiable avoidance cues or response options, such as when punishment takes place long after the event, meet the criteria of inescapable trauma. Observational learning is the learning that occurs through observing the behavior of others. This form of learning does not need reinforcement to occur; instead, a model animal is required. While the model may not be intentionally trying to instill any particular behavior, many behaviors that are observed are remembered and imitated. The domestic dog is a social species and