Advances in technology show that the human collective can learn and build upon knowledge. But if that’s true, why hasn’t human society advanced in a similar rate to its technological achievements. In other words, why hasn’t humanity worked the bugs out of its social structure. Perhaps technology, such as global communication, is a necessary component.
The differences in human groups are typically magnified by geographic isolation. Different languages or accents, as well as other cultural and physical variances, typically occur when sub-groups separate and live for a period of time in isolated or semi-isolated regions. But with global travel and global communication, humanity would tend to homogenize. Previously, any splinter group could sufficiently isolate itself so as to develop new characteristics, but this will become less likely due to the hegemony of a global society.
So perhaps it’s not that humanity is unable to socially evolve, it’s that geographic isolation made it too easy to develop distinct philosophical, cultural, and physical differences. Perhaps the development of a global network of communication is a necessary component for social evolution. And once that network is pervasive amongst all generations, perhaps a global consciousness will emerge.