Free will vs. Determinism has been one of Psychology's greatest debates. The question is whether you made the choice on your own to bring up this blog post, or whether there is some pre-determined notion that lead you to it. The debate still goes on because there is an insufficient amount of evidence to prove one way or the other, but many people have chosen their side.
The article alludes to the point that most of psychology is based off of determinism. It says, that most scientific theories are based off of the notion that one thing directly causes another. This supports determinism, which is why I was confused about how the debate is still alive today if psychologists generally agree that their theories are based off of determinism. Then I found the point, that many people want to believe that they have some say in the matter, that they have their own free will to choose what they want.
Likely, the most plausible explanation is that there is some sort of combination between free will and determinism. Our genes and subconscious behavior has already "decided" how to react in certain situations but we likely have some amount of choice when we have time to sit down and think things through before we act on them.
The article also posses an interesting phenomena that might be worth looking into, the butterfly effect.