Where I hunt in MD, the average 1.5yr old is about 110lbs and 5 pts. My club kills a couple every year that are 8 and 10pts 1.5yrs. Most are little 5,6,7's, but every now and then someone shoots a beautiful little 10. Damn shame, a 10pt yearling would be a hoss at 6.5!
Where I hunt in the pines of NJ, a 1.5yr old is a spike, or a nub, about 55-60lbs. Big difference.
I'd agree, that 5.5 didn't have any special genetics, I'd say the 1.5 would have dwarfed him at the same age.
Thanks BM.