Working with canine behaviour is not the same as training, training can help some behavioural problems with a treatment programme, but some behavioural problems are complex and need a canine behaviourist.
The breed of a dog is important as genetic breed traits need to be considered when working with dogs and recognising an individual dogs needs. Our dogs today are domesticated and have been for thousands of years, they have acclimatised to live with us based on mutual respect and trust.
How humans view dog behaviour and training has changed dramatically during recent years, we have learnt that there is no longer the need to use harsh and bullying methods, all this does is causes the dog to become quickly stressed and this causes serotonin depletion. Serotonin is a hormone that regulates mood and low levels of serotonin can result in aggressive behaviour.
Every dog is different in personality and breed, so what will work for one dog may not work for another.