Critical thinking skills can't be taught (or more accurately, programmed). They have to be developed. You may spend many years learning at a university, but never develop critical thinking skills. More and more, what I see is that educational institutions are not interested in students developing those skills, because they're difficult to measure against a rubric. Rather, there is a set, approved curriculum that is followed and the students' responses are measured against, and receive grades accordingly. You may graduate with honors - magna cum laude, even valedictorian or salutatorian and STILL not have developed that skill set. You will do well, as far as grading goes, as long as you follow the script. This is NOT the same as critical thinking skills. In fact, exercising those critical thinking skills is often contradictory to the established curriculum and sometimes even considered controversial... radical.
How do we develop those critical thinking skills then?
First, it's important to learn. Learn everything you can and from many different sources. Listen to even the most absurd perspectives without predetermined biases. That doesn't mean that you have to kowtow to every hypothesis that is presented to you. The next part is most important.
Secondly, you test those theories. Whether you take it into the lab or you break it down mathematically or using known laws. Those theories have to adhere to laws. Testing (and subsequently proving or disproving) theories takes a lot of effort. This is usually considered doctorate-level analysis, but it doesn't necessarily require doctorate-level education, or for you to be genius, for that matter. For example, if I am exposed to information stating that a particular chemical element is highly flammable, you bet I'm going to to try to replicate those results to prove/disprove that. There is a lot of misinformation or unintentionally inaccurate information floating around on the Internet. It tends to gain credence the more it is shared (or in some circles, what is called "peer reviewed"). Thousands of people claim to be "experts" on a subject without applying critical thinking skills. They are merely applying programmed responses that were taught them, according to established curriculum - and until a breakthrough is made (by someone who actually goes through the painstaking trouble of research and experimentation with tangible substances... using actual scientific methods), then the responses are only measured against status quo.
Third, it's important to be flexible... and humble enough to accept that you need further learning. It's impossible to know everything about every subject. And just because you invested your time to learn something a certain way or you spent money to pay an educator to teach you something, does not necessarily mean that it's completely factual. Sometimes, the professor or mentor teaches you on a very basic level. This is done either because the teacher may not know the subject any deeper or because the teacher cannot teach it on a basic level without leaving out pertinent facts (intentionally to avoid overwhelming the student). There are often a lot of holes in the curricula that need to be filled in later. It's impossible to teach anyone anything who already "knows" it. We have to be able to admit that maybe something we learned somewhere, even from a highly-educated professor at an accredited learning institution might be inadequate or just plain wrong. And that's ok. You learn the facts and move forward. We have to accept also that there may be more than one correct answer - maybe even appearing diametrically opposed. This is especially true in the creative arts.
Finally, never underestimate the power of your own mind. One of the first things I was "taught" in a university class was that there are no new ideas... that every idea had to come from somewhere else and that everything you submit as fact has to be cited with a credible source. This is wrong. Every human being with facilities to think has the capacity to create and to develop new ideas. Deep from within the mind can come ideas that never existed before. The simple fact that inventors come up with new products every day and writers come up with original materials attests to that. Each and every human is innately unique and we all experience life from a different perspective. We all have something we can contribute to society. When we relinquish our critical thinking in favor of scripted programming, we sell ourselves short of our potential and become just another cog in a machine that never varies in its operation.
Critical thinking develops over many years of practice in using one's mind. It's deeper than simply rote learning of facts and figures, but becoming an instrument of coming up with new facts and figures... innovating, creating, inventing and pioneering the way for others to follow, but also passing those critical skills onto posterity by encouraging children to come up with solutions to problems themselves.
