How many studies do you know in which a research team actually samples the entire world’s population? Generally scientific and even census study’s today are taken based on a number of variables. With these calculated variables added to case studies, we can prove a generalized mean and average (down to one or two percent margin of error).
Most of their data was taken without physical testing (no one was actually running a race.) The final data was proven through studies in genetic variation, heredity samples of specific allele’s in random sampled human genome’s – also weighing in things such as demography, geography, and developing traits. Chromosome mapping was a key tool.
This same team at Stanford calculated several different tests of physical performance. Things such as swimming, weight-training, gymnastic movements ect. They used 12.00 seconds because through preliminary data and suveys they felt that the 12 second barrier was the benchmark where natural ability and athletism began to really appear.
Remember – this study was based mainly on assesments of Natural Ability, and disreguarding the factor of human will.