[Godel]

If, as you assert, the brain is fully formed before birth, why does the volume of the cranial vault expand dramatically over the span of the next five-plus years?

All the neurons are present, but glial cells (helper cells), and synpases (connections) continue to grow. But of course this occurs well past birth throughout your life, and yet no one would seriously consider murdering a healthy newborn child.

[demosthenes the elder]

I will delve into the attic this saturday, so I will submit what I find in the moldy old books thereafter. In the meantime, however:

...and yet no one would seriously consider murdering a healthy newborn child.

off-the-cuff counterexamples: the modern Chinese. Bosnians, Serbs, and Croats. Nazis. WWII Japanese in China. the Aztecs. the Carthaginians. the Spartans (well, less-than-perfectly-healthy children). the Hebrews under Joshua (8:26, 7:25, 9:24, 10:28, etc...) by the command of God, no less.