You see, if somebody thinks that a person is not intelligent because he makes spelling mistakes, they must be living at least 100 years behind tjhe times
There is no agreed definition or model of intelligence.
By the Collins English Dictionary,
intelligence is ‘the ability to think, reason, and understand instead of doing things automatically or by instinct’.
By the Macmillan Dictionary,
it is ‘the ability to understand and think about things, and to gain and use knowledge’.
Is there anything in that definition about spelling. Maybe the person who wrote it could not spell it.