Experience shows them that people have different ways of being kind and communicating.
Explanation:
Jem and Scout find several gifts in the hole of the oak and at first they are happy with the things they find, but soon they are disappointed to discover that these gifts were given by Radley. That's because Radley is not a friendly, lively and communicative person. However, Jem and Scout realize that it was very kind of Radley to prepare gifts for them, just as this was Radley's way of communicating and seeking friendship.
