Final answer:
Purposive incentives are what appeals to someone's concern about a cause, encouraging them to support an organization whose goals align with their own values.
Step-by-step explanation:
The type of incentives that appeals to someone's concern about a cause is purposive incentives. These incentives motivate people to join or support an organization because they align with its goals and objectives, aiming to make a positive impact on an issue that they care about. An example of this can be seen in the surge in membership of the American Civil Liberties Union (ACLU) following the 9/11 attacks, as people joined to contribute to the protection of civil liberties they felt were at risk.