Pessimists are going to read this and call BS

A truly committed pessimist would accept this dark omen.

Anyway, this definition of optimism

> or the belief that the future will be favorable because one can control important outcomes

Isn't what one colloquially means by it.

Though it is eye catching that it will make a positive impact even if you don't, actually, control important outcomes, like by not smoking

> These relations were independent of socioeconomic status, health conditions, depression, social integration, and health behaviors (e.g., smoking, diet, and alcohol use). Overall, findings suggest optimism may be an important psychosocial resource for extending life span in older adults.

Exactly. Optimists are perpetually disappointed bitter people.

Pessimists look at anything good as an unexpected bonus.

All the good humorists are pessimists.