What does the evidence actually say about dog training methods?

That reward-based training works at least as well as methods using punishment or aversives, and that aversive methods carry documented risks — which is now the position of the major veterinary behaviour organisations rather than a matter of preference.

The two broad approaches:

Reward-based (positive reinforcement) — the dog is rewarded for behaviour you want, making it more likely. Unwanted behaviour is managed by preventing it, redirecting, or reinforcing an incompatible alternative.

Aversive-based — unwanted behaviour is suppressed using something the dog finds unpleasant: a check chain, a prong collar, an electric collar, a raised voice, physical correction, or a lead jerk.

What the research finds:

Efficacy is at least equal, and in several comparative studies reward-based training performed better on obedience and on speed of learning.

Aversive methods are associated with increased fear, anxiety and stress indicators, measured behaviourally and physiologically.

Aversive methods are associated with increased aggression, which is the outcome that matters most — punishing a warning signal such as a growl can suppress the warning while leaving the underlying fear, producing a dog that bites without warning. This is the single most important practical finding in the area.

Effects on the relationship, with dogs trained aversively showing more avoidance of their owners in tests.

Electric shock collars have been examined specifically and are banned or restricted in a number of jurisdictions, including a ban in Wales and legislation proposed elsewhere.

Why the dominance framing is outdated. Training based on being "pack leader" or "alpha" derives from studies of unrelated captive wolves, which the original researcher later repudiated — wild wolf packs are family groups, and dogs are not wolves. The framing persists in popular media and is not supported.

What actually works: reward what you want, frequently and with something the dog genuinely values; manage the environment so rehearsal of unwanted behaviour is prevented; train in short sessions; and address the underlying emotion for fear-based problems rather than the behaviour.

For serious behaviour problems, seek a qualified behaviourist through a recognised accreditation body — the industry is unregulated, and anyone may call themselves a behaviourist.

General information, not veterinary advice.