A version of this column first appeared in The Dallas Morning News and on DallasNews.com. Please check out the site. ------------ T he squabbling began a few minutes after 6:30, when my kids woke up for school. I can’t remember their topic of debate, but I’m sure it had the heft of other recent arguments over the rules of air hockey, the color of toothbrushes and who got the most sugary crumbles from the bottom of the box of Life Cereal. I sometimes feel like my sons are fast-forwarding through childhood. But as we walked to school and the bickering continued, I was reminded that they’re only 6, 8 and 11 years old. They love each other, they hate each other and everything is ridiculously competitive. The possibility that one could get more ice cream than another is nearly apocalyptic. My brother and I were the same way. Maybe even worse, because our combustible relationship featured the incendiary device of a shared room. We often had angry wrestling matches that didn’t e