At the end of WWII, the Army realized that they had made a terrible mistake. They had relied on training to prepare soldiers for specific positions.
In the field they had watched well-trained men fail at their jobs while others, with the same training, succeeded. They asked several groups of experts to analyze the situation so that they might be able to better place people into jobs in any future conflict. They all came to the same conclusion: people have behavioral styles that make them more or less likely to perform specific jobs as trained. Those who fit the job performed many times better than those who did not. The differences were dramatic. The result was the birth of the behavioral assessment industry.
While no one would argue the need and effectiveness of training, we now know conclusively that certain people will respond properly in the field while others won’t. If you want high performance, and that includes workers who operate safer, you must preselect them for the behavioral styles that match the job. Studies have conclusively shown that you can’t replace good selection with training, no mater how hard you try.