The link I sent also discusses an article that meta-analyzed replications of studies using scarcity priming. The meta-analysis includes a failed replication of a key study from the Mani et al (2013) article you discuss in your post.
The Mani article itself has the hallmarks of questionable research practices. It’s true that each experiment has about 100 participants, but given that these participants are split across 4 conditions, this is the bare minimum for the standard (n = 20-30 / group) at that time. The main results also have p-values between .01-.05, which is an indicator of p-hacking. And yes, the abnormally large effect sizes are relevant. An effect as large as is claimed by Mani et al (d=.88-.94) should be glaringly obvious. That’s close to the effect size for the association between height and weight (r = .44 → d = .98)
And more generally at this point, the default view should be that priming studies are not credible. One shouldn’t wait for a direct failed replication of any particular study. There’s enough indirect evidence that that whole approach is beset by bad practices.
I’m familiar with psychology. But the causes and consequences of poverty are beyond my expertise.
In general, I think the case for alleviating poverty doesn’t need to depend on what it does to people’s cognitive abilities. Alleviating poverty is good because poverty sucks. People in poverty have worse medical care, are less safe, have less access to quality food, etc. If someone isn’t moved by these things, then saying it also lowers IQ is kind of missing the point.
Another theme in your post is that those in poverty aren’t to blame, since it was the poverty that caused them to make their bad decisions. I think a stronger case can be made by pointing to the fact that people don’t choose where they’re born. (And this fact doesn’t depend on any dubious psychology studies.) For someone in Malawi, it will be hard to think about saving for retirement when you make $5/day.