The socialisation window in puppies — roughly 3 to 16 weeks — shapes their emotional responses for life. Poor socialisation is the leading cause of fear-based behaviour problems in adult dogs.
Dog socialisation is a welfare intervention with lifelong impact. Puppies that miss the socialisation window develop phobias, separation anxiety, and aggression that reduce their quality of life throughout adulthood. Fear is a chronic welfare state, not a momentary experience. Poorly socialised dogs often end up surrendered to shelters or euthanised for behaviour problems. Structured puppy socialisation — safe exposure to people, animals, environments, and sounds — is the highest-return welfare investment available at the start of a dog's life.