Steve is a cognitive psychologist, linguist, and popular science author. He is an advocate of evolutionary psychology and the computational theory of mind. Pinker's book The Better Angels of Our Nature  argues that violence in human societies has generally declined over time. Enlightenment Now  uses social science data to show a general improvement of the human condition over recent history. Steve is a Humanist who is also comfortable also identifying as a Sentientist given he grants moral consideration to all sentient beings. He doesn't yet seem to have applied that stance to his consumption decisions.

The closing paragraph of Enlightenment Now includes the phrase "The story belongs... to any sentient creature with the power of reason and the urge to persist in its being." The book analyses the decline in "animal cruelty" as a sign of progress yet largely ignores the clearly anti-progress story of the rapid, relentless growth of animal farming. Maybe the next edition will be titled: "Enlightenment Now: The Case for Reason, Science, Sentientism, and Progress"?

Steve on Wikipedia
@sapinker
stevenpinker.com
Steve in conversation with suspected Sentientist Stephen Fry, where he says: "To treat other people and ultimately other sentient creatures as equivalent in interests to my own."