"Why did the Hebrews need to be told these things by God, but other societies were able to work it out for themselves?"
I don't think other societies formulated the first four commandments on which the other six were based. The exclusive monotheism of Israel and rigid moral code of Israel with its personal responsibility and accountability to the one God set them apart from all the other societies who for the most part were idol worshipping polytheist who blamed their many gods for their breaking the codes of conduct. Much like what is happening today with psychiatric, economic and enviromental excuses for evil; the old Flip Wilson "the devil made me do it".
"Would that you were to examine your personal beliefs as thoroughly as you claim to examine scientific findings"
I don't remember making any claims to examining scientific findings. Perhaps you can point them out.
I never said the codes were identical, but they all have things in common: don't kill, don't steal, don't commit adultery, don't lie. Basically the rules you need to live peacefully with your neighbors.