Complete agreement that scarcity breeds more scarcity. The panic / pressure of not being able to meet basic needs no doubt is also a powerful factor affecting decisions. However, I think the IQ argument is a little overplayed.
Much of what is really happening is the that short term fixes are the rational choice — possibly the only choice- because the longer term better decision isn’t available (or is high risk). I.e. getting medical coverage makes a ton of sense and pays off if you are sick later. But you can’t make that choice if one of your other risks is your car breaking down which would cause you to loose your job.
There is no surplus / safety net. Life in poverty is often more expensive for equivalent goods / services.