Socialisation
Teaching a young dog that the ordinary world is unremarkable — not making it meet as many dogs and people as possible.
Also called: socialization · puppy socialisation · meeting other dogs
The word is the most misunderstood one in this list. Socialisation is not a quota of greetings. A puppy dragged up to thirty strangers has been socialised in the way a person is socialised by thirty handshakes at a party they wanted to leave.
What actually builds a stable adult is quiet exposure at a comfortable distance: watching traffic from a bench, hearing a pressure cooker, being near a calm older dog without being expected to play with it, meeting surfaces, lifts, umbrellas and men in helmets while nothing bad happens.
The window is roughly the first three to four months, which is uncomfortably early and overlaps with the vaccination schedule — a good reason to carry a puppy out into the world rather than to keep it home.