In his book, Seligman claims that he actually measured people's performance, and that he has evidence for all of his claims: A: That you can measure optimism;

In his book, Seligman claims that he actually measured people's performance, and that he has evidence for all of his claims: A: That you can measure optimism; B: And that it correlates with performance; C: That cognitive therapy can increase optimism; D: That the increased optimism correlates with increased performance. He published his studies, but I have not reviewed them, I am just repeating the claims from his book.