what should I study In college/university

You have three goals/criteria that are often conflicting:

1) harnessing and development of critical thinking
2) the positive impact one can have on the world around them
3) making a modest/respectable living

When I was younger, I wanted money (#3 was most important)  so I get a degree in marketing. Then when I had money, #1 and #2 became important, so I studied psychology. Philosophy would be great for #1, but it is horrible way to make a living.

All of this is my opinion, of course.

The value of a course or degree depends on your interests,skills,etc. But ill list some

1. Philosophy

2. psychology

3. economics

To develop your critical thinking skills, I would recommend psychology and philosophy, as others have. History and political science might also be good choices.

However, going to school to develop your critical thinking skills sounds like a fool's errand to me. The same corruption that grips the media infests our educational institutions. Bear in mind that the greatest propagandists - along with the people who work for the media - have college degrees, often from very prestigious universities. They generally study psychology and/or philosophy, along with "journalism" and/or political science.

I jumped into political activism years ago when I was a teacher. It was an eye-opening experience; as they say, experience is the best teacher. Yet there were still big gaps in my knowledge.

Several years ago, I began studying psychology and philosophy - but not formally. I just began exploring on my own, and it has been another eye opener. I have a much better knowledge of the problems embedded in the mind (e.g. cognitive biases) as well as the strategies used by propagandists.

My advice: Go to college to study something that can help you land a job. Work on developing critical thinking skills on your own. That includes unlearning the crap that has we've all been brainwashed with. (That may be the hardest part of the learning process.)

Incidentally, I took Philosophy 101 when I was in college and remember almost nothing about it, other than the fact that it was one of the most boring classes I've ever taken. How anyone can make philosophy boring boggles my mind. I've learned 100 times more on my own than I did from that one jackass professor.

One other tip: Writing is incredibly educational. If you have a blog, write some articles about various topics. I've long wanted to write books about psychology and philosophy in the political arena. I'm now combining them into a single book, and just organizing the project and learning the basics has been very educational.

If you don't have the time or energy to write a book, just pick ten topics that interest you - Why should we vote if there's nothing to vote for? or Who's telling the truth about 9/11? - and write articles about them. The more you learn about philosophy, the more you'll understand why some people think it's useless. ;)