User blog comment:LittleFlowerKusa/Clone Aging/@comment-24.87.61.44-20120911050828

I always thought that it was because Conner had half-Kryptonian DNA and half-Human DNA. Red Arrow has FULL human DNA, AND I'm guessing that they used about an entire arm from Roy Harper, so they had much more to work with for Red Arrow; but, obviously Superman isn't missing an arm that Cadmus used to work with.

So, I'm thinking minimal DNA material from Superman + the hybridization of two different species' DNA doesn't always turn out well. Plus, Conner was force grown in a test tube, what if they only needed him to look a certain age?

The Kryptonian DNA and Human DNA may have their growth inducing nucleotide sequences on different loci, when they combined the Kryptonian DNA and Human DNA, it's possible that both growth inducing nucleotide sequences were cut out from his DNA. Well, you may ask, "Well if he doesn't have it, how'd he grow in the first place?" Growth hormones. Growth hormones everywhere. At least, that's my take on it ._.