If your yoga practice is helping you get into a deeper relationship with your Self, then you will notice your relationships changing. When you experience your Self in that deepest state of meditation, called Samadhi -- what flows through you are feelings of love, compassion, and kindness. The awareness of your inner light shines through you. It's impossible to not care more about the people and things around you, once you experience this deeper connection to your Self.
It is when we are not in touch with this inner light that we live from a very small place. The ego governs our thinking. We look out at the world very selfishly.