In addition to the specific opportunities recommended by other comments, your brother might find Better Trajectories’ high school opportunities board helpful: https://www.hsopportunities.com/
It contains some EA and rationality focused opportunities, but also a bunch of other grants, scholarships, camps, etc
In addition to the specific opportunities recommended by other comments, your brother might find Better Trajectories’ high school opportunities board helpful: https://www.hsopportunities.com/
It contains some EA and rationality focused opportunities, but also a bunch of other grants, scholarships, camps, etc