Ethan Kross's book, "Chatter: The Voice in Our Head, Why It Matters, and How to Harness It." The excerpt examines the internal dialogue we have with ourselves, exploring its both positive and negative aspects. Kross argues that while our internal voice can be helpful in many ways, it can also lead to harmful "chatter" – negative, intrusive thoughts that can worsen our mental and physical well-being. The text then explores various techniques for controlling chatter, including self-distancing, changing how we frame stressful situations, and using placebos and rituals. Additionally, the excerpt discusses how our social interactions and physical environments can influence our internal dialogues, highlighting the importance of seeking supportive relationships and immersing ourselves in nature.