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In this episode, Drs. Derek and Laura Cabrera of Cornell University explore one of the simplest—but most profound—thinking skills: drawing the boundary between what something is and what it is not.

They unpack how this move, called Is/Is Not List, sits at the core of systems thinking and shows up in everything from team communication to personal growth. From construct validity in science to everyday misunderstandings, the Cabreras explain why most confusion, conflict, and wasted effort come from failing to define boundaries clearly.

With practical examples, from workplace misalignment to leadership clarity, they demonstrate how making distinctions transforms thinking from slow and fuzzy to fast and right. Simple doesn’t mean shallow—this episode proves that mastering the basics is the key to mastery itself.