If you want to get really technical, humans have no free will at all. We like to think we do, and for now, we are superior to computers in that our thought processes mimic free will much better, but ultimately, the ions jumping the synapses between neurons in the brain were placed there through billions of years of chain reactions. The big bang ultimately set everything in motion. Why do you think? Because a certain set of neurons connected in the right way. Why does life exist? Because a set of atoms and molecules arranged themselves into an organized mass of compounds. (Crudely put, but you get my point.) So, we are similar to computers, but our range of thoughts and emotions are far deeper and more advanced than those of modern computers. Give scientists, programmers, and mathematicians a few decades to catch up, and this will change.