Ethnocentrism is the belief in the superiority of one's own ethnic group.

Fratricide is a tragic act that involves the killing of one's own sibling.

Exogamy is the practice of marrying outside one's own social or cultural group.

Solipsism is the philosophical idea that only one's own mind is sure to exist.

Endogamy is a cultural practice of marrying within one's own social group.

It's best to mind one's own business and not interfere in other people's personal matters.

Self-denial is an act of sacrificing one's own desires or needs for the sake of others.

She helped her mother of her own accord .

Scapegoating is a harmful practice that involves blaming someone else for one's own mistakes.