Attachment to caregivers is created first through proximity during pre and early adolescence. However, as dogs develop into mid and late adolescence (see differentiation) they require far less direct social contact. During this time 10-12 hours of isolation (cumulative) becomes healthy as dogs are taught to be alone and not excessively dependent on caregivers' direct contact. Too much social contact can upset differentiation if a caregiver does not engage in proper boundary-setting. Over time, attachment transitions into a mental process whereby time and distance from social contact are less imperative. Social proximity is substituted by stability and trust in the relationship created through consistent boundary enforcement and executive authority in caregivers. The young puppy no longer sees proximity and strange situations as threatening. When this is done properly, a caregiver can increase confinement to 14-16 cumulative hours per day (or more). This helps to satisfy proper brain development in dogs as they should sleep a minimum of 14 hours each day -- especially adolescents. This still leaves 10 hours per day for proper, healthy mental and physical stimulation (eustress) via dog and human social stimulation, exploration, training, etc. In my world, overstimulation of dogs is chronic and epidemic. And our society tells us that this problem should be addressed by stimulating them further; when the real solution is to seek balance by facilitating sleep and destimulation while increasing social boundary-setting.