Jared Diamond, _Guns, Germs, and Steel_ addresses that question by comparing societies that were geographically isolated (and thus could count only on sel-development) to those that were not (and thus cross-polinated one another so to speak). His conclusions are that self-development does not lead anywhere but backwardness and stangantion.
"Self-development" is a ruse invented by thrid world nationalists and the "noble savage" intellectuals in the developed world.
Wojtek