There are a lot of different reasons as to why punishment for dogs is used, and very often without thinking about the consequences and implications. Very often, a lack of knowledge and education can contribute to the use of punishment. Another factor can be that a trainer told them to do so and not knowing any different they just do it. It could also be the fact that it might have worked temporarily and so they carry on doing it. Frustration can play a big part in its use. It can also be a reflex action and sometimes the fact of feeling in control.