Objectively speaking, intelligence is considered to be the ability to reason. Following that line, high intelligence would be the ability to reason well.

However, we humans do well because we specialize. It was discovered early on that we can't do everything. One could say it's our individuality which drives us towards having different proficiencies and the entire chain of schooling would better serve to explore and encourage pursuing such specializations.

Where the means to cultivate proficiency are lacking, the end result will often be incomplete. That shouldn't mean there is a lack of intelligence, but that it hasn't been developed to its potential. I would say.. the base intelligence remains the same while expectations rise in concert with each own's path of development.

Life is neither easy nor fair. And opportunities aren't equal. So i often try to remind myself that perspective changes with experience and as such any standard we set ourselves and others to tend to be laced with personal bias.