Did you answer that the ball was 10¢ or did you correctly calculate that the answer that the ball cost only 5¢? If the first, then this research has "actual life" relevance for you, personall!y
If you are in business, it means the majority of your "smart" employees would get the answer to a simple arithmetic problem WRONG! That's "relevance to real life!"
It's why the electorate of California continue to re-elect the same Democrats that have put them into this mess, election after election, hoping for a better result! That's relevance.
In business, you do not encounter such inane questions. Not even accountants and actuaries do; certainly shipping clerks do not. If you’re going to say that this is relevant to real life, please demonstrate how instead of being rhetorical.
It's not just a question of IQ (three standard deviations above the mean in my case); or trained thinking - rationality has been more or less "instinctive" for me since early childhood.
I think the point is most folks, smart or not, are intellectually lazy and dishonest. If you are looking for short-cuts in thinking and not too scrupulous about what is actually the truth of the matter, sure you're going to make mistakes in your thinking.