Intelligence Enhancement – The ability to enhance the intelligence of others.
The Brain Coral Fields in the SpongeBob universe can make a character more intelligent.
In Charly (1968), Charly is intellectually disabled but receives an experimental treatment that dramatically raises his intelligence.
According to Pat Mills, if you raised the IQs of South American children then many would turn to Marxism (Marshal Law #5, Epic Comics)!
Krypto (DC) has his intelligence enhanced by red kryptonite in Superman V1 #177.