According to Jonathan Haidt (“The Righteous Mind”) we - our rational minds that we take such pride in anyway! - are like the rider on top of an elephant (the elephant being our intuitional self). The elephant is really the one in charge of all immediate reactions and where it’s going to go. The rider on top is good at providing post-hoc justification for where the elephant is going. The elephant can be influenced by the rider, and (in rare cases) may even change its course accordingly. But our main mode of operation is that the elephant will do what it will do, and our reasoning has evolved, not to find truth, but to find rationale that will help us look justified to others.
In other words, our so-called “rationalism” turns out to be a lawyer helping us preserve our own reputation in the eyes of our own tribal group, rather than a scientist trying to help us discover truth. We (according to Haidt and a whole lot of research to back him up!) are not truth-seekers, but reputation seekers. …but we will give lip service and homage to truth whenever we think we will be held accountable to some larger group that we perceive will itself have that same concern. That’s why no single person isolated from any perceived accountability (even ostensibly ‘honest’ ones, which so many of us think we are) will be any good at teasing this stuff out, but large groups of us from diverse interests and tribes that manage to maintain a bond of accountability to each other become much more likely to (together) converge on something closer to truth.