Brett Kavanaugh Questions IQ Test Averages in Hamm v. Smith Oral Arguments

Permissible IQ Test Amendment Approaches

• 💡 The Petitioner's attorney, Robert M. Overing, outlines several permissible amendment approaches for states when dealing with multiple IQ scores.
• 🎯 One approach discussed is the median score, which states can use if it exceeds 70, considered a safe harbor according to the APA handbook.
• 🧩 Another method is the overlap approach, which examines the common numbers within the error ranges of each score.
• ⚠️ If the bottom of the overlap error range is 69 or 70, it doesn't necessarily indicate a greater than 50% chance of the IQ being below 70.
• 📈 The attorney states that in this specific case, the bottom of the overlap is 73, with a potential range of 73 to 77 or 78.

Alternative IQ Score Methods

• 📊 The composite score method is presented as another option for states, with the average serving as a rough approximation.
• 🧐 However, Justice Kavanaugh expresses skepticism about the accuracy of using averages for IQ scores.
• 🚀 A fifth method involves looking at the high score, particularly if its entire error range is above 70, as higher scores are considered more probative due to fewer ways scores can err upward.

Rationale for Limiting Court Review

• ⚖️ The attorney argues against allowing trial courts to delve deeper into other evidence once a safe harbor method is met, stating the adaptive behavior prong is not as reliable as IQ.
• 🧠 He suggests that weighing subjective adaptive behavior evidence against objective IQ scores is beyond the capacity of courts.
• 📚 Disagreements among experts regarding the definition and measurement of adaptive behavior, with hundreds of different scales and significant judgment involved, make it difficult to standardize.
• ⚠️ The attorney points to inconsistencies in how courts handle evidence, citing an example where a reading comprehension test showing 11th-grade literacy was downplayed in favor of earlier, less indicative evidence.