Re: So they were at least as smart as some modern Human populations.
Not the same.
Timescales are way different.
Ntal technology and culture remained static over nx10exp5 years.
These neolithic humans are stuck at worst at pre-agriculture just 10exp4 years ago.
Without a large population civilization it's really hard to have the leisure class to advance much in arts and sciences. The world today does not allow a neolithic group to expand and create its own civilization.