When should you trust your gut? How should you trust your gut at margins where, intellectually, you know you shouldn't? When building your intuition and your gut goes against your intellect, trust and go with your gut. The rationale of that claim is this: Assume your gut is (always) correct. You could do this at different margins, or you could do it on aggregate. This way of thinking mirrors a concept in statistics called hypothesis testing. Here's how it works: You have a null hypothesis (written as "Ho," which is the default hypothesis) and the alternative hypothesis (written as "Ha," which is the hypothesis that differs from the null). You get data and test if there is sufficient evidence to reject the null, i.e., you have enough evidence to say that your alternative hypothesis is correct. (Statisticians are probably ripping their hair out at this point because the interpretation is slightly inaccurate, but that'll do for now.) Or fail to reject the null, i.e., the null is correct. To implement this in your own life, set up the problem this way:
Ho: My gut is correct
Ha: My gut is not correct.
One should then check with the outcome of the event for which the test was done to determine the proper conclusion. We could push this further and use other statistical methods to test errors and such, but the broader point is that your default assumption should be that your gut is correct, and here's why:
You are alive: The fact that you're alive means, evolutionarily, you have about 300,000 years of gut honing by nature. This gut of yours, crafted for survival, is augmented by your parents, who are (hopefully) better versions of their parents, iteratively over time.
The philosophical problem of knowing i.e. Epistemology: One can know things intellectually but cannot implement them in their everyday lives. This does not discount the joy of expressing to people that you know a thing. In fact, Aristotle saw this as a considerable part of your decision-making process to pursue curiosity. The point is this one can have fancy models and rationality augmenting tidbits, but probably the best rational tidbit is to follow your gut at most margins.
That said, over time, your mental models and modules can shape your intuition. This view, for me, is most implementable in physical activities. In my specific martial art (email me your best guess of what you think it is), one of the best ways I know that I have a move down is how it feels to perform. I might know all the technical details, but in most cases, once I complete the specific movement, I know if I have it down or not. "It doesn't feel like *insert my martial art here*" Like I always say. In this instance, I did not get a sense of my martial arts until I had done a couple of moves using every detail and truly knowing what that feels like. Motions can be taught, but it has to be integrated into one's body. Your gut (through nature) has basically done virtually all of that for you, so tweak at the edges.
Certainty rating: 70%