I would need to know what the actual task is, but isn't that obvious? If I ask adults "What's 2+2" in a language they don't understand and I ask the same question to children in their native language, the children will look smarter than the adults.
> .. the most important thing about any communications medium is that message receipt is really message recovery: anyone who wishes to receive a message embedded in a medium must first have internalized the medium so it can be “subtracted” out to leave the message behind.
(a tangent, but perhaps interesting)