There are times when it can be irrational, such as with approach anxiety.
But other times, it's dead on. Normally it's the first indication when something is wrong, but your rational mind doesn't want to accept it. A lot of communication is nonverbal, and our subconscious may be capable of processing loads of red flags our conscious mind doesn't pick up on. I think there's a lot of things we're programmed to believe, and social expectations we're supposed to observe. But at a base level, we have instincts that can push through all the programming to send alarm bells ringing when something isn't right.
But other times, it's dead on. Normally it's the first indication when something is wrong, but your rational mind doesn't want to accept it. A lot of communication is nonverbal, and our subconscious may be capable of processing loads of red flags our conscious mind doesn't pick up on. I think there's a lot of things we're programmed to believe, and social expectations we're supposed to observe. But at a base level, we have instincts that can push through all the programming to send alarm bells ringing when something isn't right.