Conditioning of the response to pheromones begins at birth

Mice are mammals, which indicates that the same process is involved in humans.

Mouse nose nerve cells mature after birth, allowing bonding, recognition with mother

For rodent pups, bonding with mom isn’t hard-wired in the womb. It develops over the first few weeks of life, which is achieved by their maturing sense of smell, possibly allowing these mammals a survival advantage by learning to identify mother, siblings, and home.