Im from a big family and there is sorta a gulf because of some babies that did not make it. My eldest brother had many cavities and he was great with his diet and oral care. Im at the other end of the spectrum as the youngest male and had an aweful diet. Hooked on pop and love sweets and I did not brush my teeth regularly and had few and they were all so slight I had them done without novacain. This actually plays out for both the oldest two and youngest three with the middle ones being in between. Seemed to make a difference.