Dealing with a selfish brother, whether he is younger or older, can try your patience. Your brother might demand that everyone pay attention to him or give him the best of whatever is available. If your parents allow this behavior, he isn’t likely to change until he discovers that the rest of the world won’t tolerate it. Consider setting boundaries, treating him with love and denying him your attention when he acts out.

Selfishness and Immaturity

Your brother’s behavior could be the result of immaturity. He will grow out of it, according to psychologist Marie Hartwell-Walker in “Why Is My Sister So Selfish?” for Psych Central. Remind him that selfish behavior is inappropriate and will not attract friends. Explain that cooperation and selfless behavior will get him further in life. Encourage him to learn team skills through activities such as sports and games or cooperative projects. Be patient and hope he grows out of it.

Turn Off the Spotlight

When your brother acts out in a bid for attention, turn off the spotlight by ignoring him and focusing on something you enjoy doing, suggests sociologist Martha Beck in “4 Ways to Defend Yourself Against Emotional Pirates” for Oprah.com. See to your own needs when he demands that you give him what he wants, reminding him that his behavior encourages opposition rather than cooperation. Put on your headphones and tune him out or walk away. If you no longer live together, hang up when he becomes rude or attempts to coerce you into letting him have his way.

Set Boundaries

Set boundaries for the behavior you will tolerate, suggests psychologist Roya R. Rad in "How to Deal With Self-Centered People” for the Huffington Post website. For example, keep him out of your room or refuse to include him in an outing if he behaves selfishly. Spend as little time as you can with him, perhaps studying at the library or withdrawing to your room with the door closed. Don’t rise to the occasion if he tries to bully or insult you. If you must disagree with him, keep the comments short and informational rather than attacking him or engaging in a long explanation, Rad suggests.

Don't Compromise

Stay true to yourself and refuse to respond in kind. Treat him the way you want to be treated. Refuse to be a doormat. Your mature behavior could encourage him to rethink his actions more effectively than a lecture.