It’s probably mostly a side effect of our ability to feel love for each other.
As a group animal we have an instinct to protect each other that is born from love, that instinct help us survive as a group. The pet is included and can become part of the group maybe even family.
This trait has also helped us build relations with some animals that have historically been beneficial to our survival, like dogs horses and farm animals. For less immediately “useful” pets, the instinct is the same, and although it doesn’t serve the same purpose, it may be helpful psychologically to overcome hardship, and maybe tie the group together more closely.
It’s probably mostly a side effect of our ability to feel love for each other.
As a group animal we have an instinct to protect each other that is born from love, that instinct help us survive as a group. The pet is included and can become part of the group maybe even family.
This trait has also helped us build relations with some animals that have historically been beneficial to our survival, like dogs horses and farm animals. For less immediately “useful” pets, the instinct is the same, and although it doesn’t serve the same purpose, it may be helpful psychologically to overcome hardship, and maybe tie the group together more closely.