I recently found out that Alfred Binet, who is credited with inventing the first intelligence test, apparently did not believe it was measuring fixed innate ability. That seems like a pretty significant disconnect from how IQ tests are used and interpreted today. How did we get from Binet’s original cautious practical tool to the modern concept of IQ as a measure of innate cognitive capacity?
This is one of the most fascinating and honestly kind of uncomfortable gaps between a scientist’s intentions and how their work got used. Binet designed his test in 1905 purely as a practical screening tool to identify children needing extra educational support in French schools. He explicitly warned against treating scores as measures of fixed inherited intelligence and believed cognitive ability could be improved with the right intervention. The transformation happened largely through Lewis Terman at Stanford who adapted Binets work, introduced hereditarian interpretations, and used it to argue for fixed innate differences between groups. Terman essentially took Binets cautious practical instrument and turned it into a theoretical statement about innate ability that Binet never intended 
Scientists losing control of how their work gets interpreted is a recurring theme in psychology honestly 
Binet wanted a practical classroom tool and ended up founding an entire field that spent decades arguing about nature versus nurture. The gap between what he intended and what happened is pretty striking 