You’ve probably heard the claim that sleep training—especially methods like "cry-it-out"—can flood babies with toxic stress. But is that actually what the science says? In this episode, I sit down with a leading developmental expert to unpack the research on cortisol, stress, and infant development. We cover how the stress response system works, what truly qualifies as toxic stress, and why common fears about sleep training may be missing important context. Whether you're team sleep-train or not, this episode offers clarity, compassion, and evidence-backed guidance. Key Takeaways: Cortisol is a normal, necessary hormone that helps us respond to stress. Not all stress is toxic—especially when it’s brief and supported by a caregiver. There's no evidence linking sleep training with long-term harm. Misinterpreting small or flawed studies can create unnecessary fear for parents. Sleep training, when developmentally appropriate, can be a positive and adaptive experience for both babies and parents. Our podcasts are also now on YouTube. If you prefer a video podcast with closed captioning, check us out there and ⁠subscribe to PedsDocTalk⁠. Get trusted pediatric advice, relatable parenting insights, and evidence-based tips delivered straight to your inbox—join thousands of parents who rely on the PDT newsletter to stay informed, supported, and confident. ⁠⁠⁠⁠Join the newsletter⁠⁠⁠⁠! And don’t forget to follow ⁠⁠⁠⁠@pedsdoctalkpodcast⁠⁠⁠⁠ on Instagram—our new space just for parents looking for real talk and real support. We love the sponsors that make this show possible! You can always find all the special deals and codes for all our current sponsors on the ⁠PedsDocTalk Podcast Sponsorships⁠ page of the website.  Learn more about your ad choices. Visit podcastchoices.com/adchoices