In this episode, we take a measured look at the history, science, and ongoing debate surrounding IQ testing. From the early days of phrenology and Galton’s eugenic ideas to the development of modern psychometric models like the Cattell-Horn-Carroll theory, we trace how intelligence has been defined, measured, and contested over time. No pseudoscientific hyperbole;just some balanced, nuanced, and expert-led science. 📚 Chapters:00:00 – Introduction: What is IQ, really?01:20 – The Origins of Intelligence Measurement (and Dark History)04:00 – The First True IQ Test (and Formula)04:40 – The Problems with the 'IQ Formula'05:50 – Norm-Referenced and Standardized IQ Testing 07:20 – Spearman’s g, the 'g factor', and the 'Positive Manifold'09:40 – How to Create and Validate an IQ Test10:41 – IQ Test Example Questions (loaded on your 'g factor')15:10 – The Globalization of IQ Tests (and some UGLY truths)18:20 – Cultural Fairness and Bias in IQ Testing (Fluid vs Crystallised Intelligence)26:30 – The Structure of IQ Today (CHC Theory)26:30 – The Structure of IQ Today (CHC Theory)29:30 – What Do IQ Scores Actually Mean?30:05 – Outro: IQ and Causality CaveatsAlong the way, we consider:*The origins of IQ and its evolution from Binet’s educational aims to Wechsler’s multi-domain models*The varied ways IQ tests have been used—for support, for sorting, and at times, for exclusion*What Spearman’s g actually represents, and how it shaped the structure of modern tests*The distinction between fluid and crystallised intelligence, and why it matters*Some examples of IQ test items that have been scientifically validated to tap your 'g factor'*How modern statistical methods are trying to address longstanding limitations with cultural biasWhether you're a student, teacher, psychologist, or simply interested in the science of human potential, this video offers a thoughtful exploration of what IQ tests can (and can’t) tell us. A Note on Scientific Integrity: If, like me, you’re wary of the pseudoscientific noise that often surrounds topics like intelligence, rest assured that this video has been reviewed for accuracy and balance by Luke Rowe, who holds a Ph.D. on the topic of intelligence, its role in learning and social dynamics, and psychometric testing. The goal is to avoid the two common traps found in popular commentary: the overclaim that IQ explains *everything*, and the counterclaim that IQ explains *nothing*. Both positions are misleading. As is often the case in science, the reality is more complex (and more interesting!). The approach here is grounded in the general consensus of contemporary intelligence research, while acknowledging its many nuances, limitations, and ongoing debates.Want More?Stay tuned for upcoming videos exploring the biggest problems with IQ testing, how we define and measure notions of 'gifted' or 'genius', and how (and whether) we can improve intelligence (even if we can boost our IQ). 🎓 About Me: I’m Luke Rowe, Ph.D. in learning sciences, and I’m passionate about sharing the latest insights from brain and learning science to help you learn, teach, and thrive.👍 Enjoyed the episode? share the love by 'liking' or leaving a positive review. Subscribe 🔔 for more on the science of learning and intelligence.Comment 💬 below with your thoughts or questions.🔗 Stay Connected: Available on Spotify, Apple Podcasts, and YouTube.📢 Share this video with someone who wants to understand intelligence!DISCLAIMER: The views expressed in this episode are solely those of the creator, Luke Rowe, and do not reflect the views or interests of any past, present, or future institutions or employers.