I'll simply say that there is such a thing as objective rationality and reason. For example, if their is research proving that there are 10,000 Germans in the country it is not then rational to read that research and then declare that you refuse to believe it because your gut instinct is that there are hundreds of thousands of Germans in the country and you will favour trusting in your flawed perception of the world even when you have evidence proving your perception wrong.
And if you would say that there is no such thing as objective rationality and reason then please explain to me the existence of logic.
Though when you say that the human mind does not operate objectively you are actually agreeing with what I am saying - the human mind does not normally operate in an objective fashion, and never all the time, but it is capable of operating objectively on occasion which is what we call being rational as opposed to being irrational. You can look at a situation, seek to obtain all the facts and then make a logical decision based on the information you have available. That is evidence based decision making which is rational. You could also look at a situation, ignore all the facts and then make an illogical decision based on gut instinct or emotion. That is irrational decision making.
And, if you wish a real life example, there is no particular policy reason why I should not vote Labour in this election, particularly as my main priority is to keep the Conservatives out. However, I voted Liberal out of emotional attachment to that party despite having no real policy reason to do so. Therefore, I voted irrationally.
Who defines that 'objective rationality'? Some exogenous force, or a human being with a subjective opinion?
Perhaps you? A council of old wise men? Philosophers? Central planning committee?
In the example of research, you might have heard that the paper lies about facts; you thus have a good reason (rationale) to doubt the results. Maybe a friend told you the research is wrong, and you really trust you friend. Just because it is written on a paper, by some human that you have never met, who has happened to get the title of a professor, does not make the research results objective truth.
Gut instincts can be rational. Why else would you get the feeling of a gut instinct, if not based upon apriori experience?
Logic... it is based upon generally accepted apriori experience. It takes one thing granted, and then proceeds to draw conclusion from the first fact, that the second fact that derives from the first assumption might also be true. Like piling rocks atop each other, you can draw conclusions from existing already made conclusions. But in the beginning, it is just a mere assumption, such as assuming 1+1=2. Maybe you can even prove this assumption!
Logic works with metaphysical ideas.
But humans are animals, and not subject to laws of nature. There are no 'laws of sociology' or psychology that define human behaviour, or make A a rational choice but say B is not a rational choice. Humans are in constant change, there are no constant laws. The laws can apply simply to a specific location, time, circumstances and known facts. But in reality everything we do and think is in continuous movement! The beauty of human nature is our constant change, striving for a better future!
When talking about humans; I repeat again, throw objectivity out of the window.
Because you make decisions upon emotion or gut feeling, does not make the decisions irrational or illogical. There are some written data in our genes that promote gut feeling, in order to keep us alive. A gut feeling is rarely wrong, thus following it is a very rational and a good choice. Gut feeling, as it is, a evolutionary measure to keep us alive. Following your feelings can be very very rational.
After all, feelings are based on apriori experience. You know feelings have guided you before, therefore letting feelings guide is a good choice once again. And what are our opinions, if feelings in our brain?
They are chemical reactions that happen in our brain, in reaction to recent data the brain gathers, which it compares to experience gained before; when it is making a decisions. A rational decisions, based upon the best possible data known to the brain.
You voted very rationally.