If you have the impression that humans do not often think about things you are not alone and may be correct.

Mark Twain, a skeptic of the idea of free will, argues in his essay "What Is Man?" that humans do not command their minds or the opinions they form.

"You did not form that [opinion]," a speaker identified as "old man" says in the essay. "Your [mental] machinery did it for you—automatically and instantly, without reflection or the need of it."

Twain's views get a boost this week from researchers at Washington University School of Medicine in St. Louis and University of Chieti, Italy. In Nature Neuroscience, scientists report that a simple decision-making task does not involve the frontal lobes, where many of the higher aspects of human cognition, including self-awareness, are thought to originate. Instead, the regions that decide are the same brain regions that receive stimuli relevant to the decision and control the body's response to it.

Other researchers had already demonstrated the same principle in primates. But many still assumed that the more complex human brain would have a more general decision-making module that involved the frontal lobe independently of the neural systems for perception and action.

I think that the Twain essay is worth further attention.

Where the temperament is two-thirds happy, or two-thirds unhappy, no political or religious beliefs can change the proportions. The vast majority of temperaments are pretty equally balanced; the intensities are absent, and this enables a nation to learn to accommodate itself to its political and religious circumstances and like them, be satisfied with them, at last prefer them. Nations do not THINK, they only FEEL. They get their feelings at second hand through their temperaments, not their brains. A nation can be brought-- by force of circumstances, not argument--to reconcile itself to ANY KIND OF GOVERNMENT OR RELIGION THAT CAN BE DEVISED; in time it will fit itself to the required conditions; later, it will prefer them and will fiercely fight for them. As instances, you have all history: the Greeks, the Romans, the Persians, the Egyptians, the Russians, the Germans, the French, the English, the Spaniards, the Americans, the South Americans, the Japanese, the Chinese, the Hindus, the Turks--a thousand wild and tame religions, every kind of government that can be thought of, from tiger to house-cat, each nation KNOWING it has the only true religion and the only sane system of government, each despising all the others, each an ass and not suspecting it, each proud of its fancied supremacy, each perfectly sure it is the pet of God, each without undoubting confidence summoning Him to take command in time of war, each surprised when He goes over to the enemy, but by habit able to excuse it and resume compliments--in a word, the whole human race content, always content, persistently content, indestructibly content, happy, thankful, proud, NO MATTER WHAT ITS RELIGION IS, NOR WHETHER ITS MASTER BE TIGER OR HOUSE-CAT. Am I stating facts? You know I am. Is the human race cheerful? You know it is. Considering what it can stand, and be happy, you do me too much honor when you think that _I_ can place before it a system of plain cold facts that can take the cheerfulness out of it. Nothing can do that. Everything has been tried. Without success. I beg you not to be troubled.