Critical thinking plays a large role in ethics because it is the process by which we determine for ourselves whether or not something is right or wrong. In a sense, critical thinking is a form of analysis and determination of fact vs. fiction, identifying the unknown, coming to an understanding, etc… By taking the path of a critical thinker, a person develops a mental process of evaluation which helps to determine their ethical standards.
By incorporating the critical thinking process into their mindset, it enables them to more effectively make decisions based upon truths and verified information, rather than unknowns and variables. By eliminating the variables, you bring to view the plain truths which exist and make a decision based upon that. Having a critical approach to ethical analysis is very important and remains one of the principle factors as far as I am concerned.
I think that people should have a very analytical mind if they are to be truly successful ethically, because it is too easy to forget and not care; resorting to self sufficient forms of thinking and ensuring your own survival, etc… I think a lot of people who have had hard lives are forced to make decisions they would not choose to make otherwise had they not been in that situation at the time, but needed to make the choice that would best benefit them personally because of the extreme nature of their lives.
This is applicable to cultures all over the world and I am confident that if you are a smart person and understand the concept, critical thinking applied to ethical and moral standard analysis is something that is essential to your success and if not implemented in the proper manner (i.e. making poor decisions) can lead to negative outcomes.