My older kids (9 and 12) can be very me-centric. For instance, we recently won a small amount of money from a contest, my now 12 year old immediately suggested that we spend the extra money on his birthday. Anytime he thinks he can convince anyone to spend money on him, he'll do it. Whether it be friends, grandma, us, or his siblings, he somehow manages to try and convince all of them to spend money on him. What can I do to dissuade this habit?
Being altruistic takes practice. Part of that practice is being able to put yourself in another person's place and imagine experiencing what they are feeling.
We started encouraging this with our kids by giving them things to share. Here are some examples of things we say to our kids:
"Here's one cookie for you, and this one is for YOU to share with your brother" - they are taking responsibility for the sharing. Then the follow-up - "How did your brother feel when you gave him the cookie?"
"We need to buy party favours for your friends. You have $X per person. What do you think they would like?" - Then at party, THEY give out the favours to their friends and thank them for coming.
"Here is your allowance. Some is for you to spend now. Some is for you to save. Some is for you to help others." Start with equal portions. Discuss charities/organizations they might like to support. Then be sure they get to see the effect of their generosity.
Insist on manners first. Show them how to be a good host. Comment on people who are good hosts by pointing out their generosity and how it made you feel. Sometimes point out the opposite, but only occasionally. Eventually they will catch on.
Remember: tangible rewards for altruism decrease the likelihood that it will happen again. The reward is just feeling good. Revel in it and help your kids revel in it!
Also, older kids might be trying out humor. In this instance, even if they weren't, I'd laugh off the birthday comment and refocus on a more equitable/realistc purpose for the money.
Quite simply: stop doing it, stop letting the siblings and grandparents do it.
The behavior will only persist as long as he believes it will work. When he consistently gets offense or irritation or surprise as a reaction instead of gifts, money, and other treats, it won't be a worthwhile behavior any more.
I would think of this as a gift that your son has. He has an amazing power of persuasion. Can you help him channel this persuasion towards achieving greater accomplishments? Can he write a business plan and get people to fund his business idea? Can he convince people to donate money to a great charity? Be creative. Help him be creative. Harness his strengths.