Human's and other living (thinking) beings have "pre-programmed" instructions in our DNA, they affect our behavior on a subconscious level and it reflects in our actions. This can be seen in animals survival instinct for example. Through time populations may change the instructions in their DNA, this is caused by repeated actions over time. This can even be seen physically, like wisdom teeth in humans. Just in that, we can clearly see that for now at least, humans and how they think is on a different level than just thoughts, its hundreds of thousands of years of evolution that has brought us here.