I am left handed and right eye dominate.  My dad bought me a left handed little bear bow when I was 8 years old.  He quickly figured out that I was right eye dominate and exchanged the bow for a right hander.  I am very glad that he did.  It was very easy for me at that age to learn to shoot right handed.

Not that I think my viewpoint is the absolute only way to go......but, please keep in mind that everyone responding is over the age of 10 and can only relate what they know now (and maybe  wish they would have done if they could go back and do it over again.....

If I had to do it over again (not my shooting, but teaching my son), I would have laid off worrying about which way he could ultimately shoot the very best in order to keep it something he enjoyed doing.  IMO, don't lose sight of that.

So, if I were in your shoes, I would introduce him to shooting LH, but back off and allow RH if he balks at the ackwardness of using the "off" hand.  If he grows up to be as passionate about it as those of us here, then he may want to make the change.  

Then, he will probably post on a forum such as this and say "I wish I would have started out LH"