In so far as we form part of the animal kingdom our own safety, property, food, dominance, and the reproduction of our own type, are inevitably the first objects of our instinctive care.

Civilized life has disguised some of these crude demands and the behaviour which is inspired by them, but their essential character remains unchanged.

Love and hate, fear and wonder, self-assertion and self-abasement, the gregarious, the acquisitive, the constructive tendencies, are all expressions of instinctive feeling; and can be traced back to our simplest animal needs.
But instincts are not fixed tendencies: they are adaptable.

This can be seen clearly in the case of animals whose environment Is artificially changed.

In the dog, for instance, loyalty to the interests of the pack has become loyalty to his master's household.