Dog Socialization: How To Avoid A Problematic Canine That Attacks Other Pets And People! ... The Critical Period The critical period of socialization is that time when a certain set or patterns of genetically oriented behavior must be performed or presented to a developing animal (in this case a puppy) in order for such behavior to manifest in the animal when it is older... The critical period in dogs varies for the different dog breeds, but as a species in general, the critical period of socialization in dogs extends from 2 weeks to 16 weeks...