selfishness
Egoismo is the Italian word for selfishness. It is used to describe the act of being excessively preoccupied with one's own advantage at the expense of others. In Italian, egoismo is considered a negative trait, just like in English.
His selfishness ruined our friendship.
In this example, it implies that a person’s selfish behavior has negatively impacted a relationship, causing it to end.
Selfishness is not a virtue.
This sentence establishes a value judgment in regards to selfishness - it's considered as not being a virtue.
Avoiding selfishness can improve interpersonal relationships.
This sentence proposes a piece of advice regarding interpersonal relationships - they can be improved if one avoids selfish behavior.