Kelvin demonstrates integrity and kindness through his actions. By choosing to return the wallet to the old woman after finding it, he shows a sense of moral responsibility and respect for others' belongings.
The text states that he "walked to the woman's house" to return the wallet. This indicates that he went out of his way to ensure the wallet was returned to its rightful owner. His decision to remove the ID and seek out the woman highlights his empathy and a desire to do the right thing, rather than keeping the wallet for himself or ignoring the situation. This selflessness and consideration for another person's loss exemplify strong character traits of integrity and kindness.