Instead of thinking Attitude is the winner of a competition with Intelligence, understand Attitude is a subset of Intelligence or, better still, understand Attitude is an outcome of Intelligence.
The folks who came up with the 'Fish Philosophy' have it right - "Choose Your Attitude". And, if you embrace that advice, your Intelligence will guide your choice and you will select a good/winning/positive Attitude.
Attitude, whether good or bad or indifferent, is not an innate trait of character.
Attitude is a choice.
Good/winning/positive Attitude is an intelligent choice.
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We can split Intelligence into two general components: logical intelligence and emotional intelligence. Logical intelligence tells us we must choose a good Attitude over a bad one...so much upside...no downside. Of more importance, logical intelligence tells us emotional intelligence will have to be most-diligent to help good Attitude remain good in the faces of the ongoing challenges it will regularly encounter.