The people who think about thinking say that very few of us ever look at facts and make a decision. In almost all cases, they say, we make choices almost instantaneously and then spend our time building a case and looking for things that support our biased choice. They say this is mostly true whether we are thinking about brands of pork-and-beans or which religion to sign up for.
This shouldn’t be a surprise. It’s only recently in our history that humans have had the time and luxury and cultural environment to lay about and think about things. Certainly, we’ve been a curious species since we climbed down from the trees. We watch chimps and apes and see that they are curious, too. Figuring out how your environment works is important for survival, especially in novel or changing environments.
Like all animals, though, humans are primarily made for quick decisions. When we are walking in the woods and come upon strangers from another clan there is no time for thinking. The one second that you stop to wonder about whether these folks are friendly or not just might be the time it takes for the newcomer to skewer you with an obsidian-tipped spear. So we instantly assess the situation. How are they standing? What is their facial expression? Do they have weapons? Are they young and strong or old and sagging? We see all of these things instantaneously and then flee, attack, smile, or wait. None of this goes away just because we are modern and think we’re smarter than our ancient brethren.