@Tfmonkey Weakness maybe is a product of IQ. Two things come to mind, 1) the marshmallow test that showed how those who can delay gratification do better in life, and 2) the "what if you didn't have breakfast today" question, that some people apparently cannot answer as it depends on a hypothetical, an abstract.
I haven't investigated either of these first hand so maybe they're not as they seem.......
@TfmonkeyBut it does seem that a lack of vision or long term goal setting/following correlates with struggling more in life. To paraphrase a Nietzsche (I think) quote Jordan Peterson has said many times, 'he who has a why can withstand any how'. A long projected goal may depend on some level of intelligence. An exception might be faith, but that would be an abstracted ideal like heaven or redemption or benevolent goddess; or just the prospect of reproducing.
Just my thoughts. Interesting questn