Even TFA says it very clearly: they find a correlation. However, the title and introduction desperately want to imply causation. However, the causation can run all sorts of ways - and the study itself does not (and, indeed, cannot) say which of these is correct. Just to name three possibilities:
- Poverty hinders brain development (what the SJWs want to hear)
- People with a genetic predisposition for poor brain development tend to be poor (definitely not what the SJWs want to hear)
- Poverty correlates to certain activities (or lack thereof, for example, little reading). The lack of those activities hinders brain development. This can mimic genetics to an extent, since behavior is passed along from parents to children. (Complicated, not news worthy, and therefore likely to be closer to the truth).
So, erase the provocative title, ignore the introduction (that tries to inspire the SJW in all of us), and the study itself is interesting. However, actually determining the causation is the critical part, and that's not done yet...