Causation is measure of the extent to which they contain different information.
Assuming a college wants to admit a student with high "intelligence" or intellectual potential, which cannot be measured directly.
If high income causes high SAT, and high intelligence also causes high SAT, then (low income, high SAT) may well indicate much higher intellectual potential than (high income, high SAT)
If high income and SAT are both caused by high intelligence, then there is less (intelligence-related) reason to prefer (high income, low SAT) or (low income, high SAT).
Assuming a college wants to admit a student with high "intelligence" or intellectual potential, which cannot be measured directly.
If high income causes high SAT, and high intelligence also causes high SAT, then (low income, high SAT) may well indicate much higher intellectual potential than (high income, high SAT)
If high income and SAT are both caused by high intelligence, then there is less (intelligence-related) reason to prefer (high income, low SAT) or (low income, high SAT).