Q.  I fail to understand how some people don't seem to experience any remorse when they exhibit behaviors that are very hurtful to others. Don’t they have a conscience? Is this a brain thing?

A. The short answer is “probably.” The brains of individuals who exhibit the type of behavior you described may differ from the brains of those who experience remorse for their hurtful actions. Although it is still a puzzle in terms of development, studies have shown that this type of brain (often referred to as a sociopathic brain) is more than just the absence of conscience. It involves an inability to process emotional experiences (including caring and love) except when such an experience can be calculated as a coldly intellectual task.

Dr. Martha Stout has estimated that 4% of the population in America fall into this category. Studies have shown that the sociopathic brain responds to emotionally charged words no differently from neutral words (unlike the non-sociopathic population). In addition, research using single-photon emission-computed tomography showed increased blood flow to the temporal lobes when the sociopathic brain was given a decisional task that involved emotional words, a task that would be almost neurologically instantaneous for normal brains. The sociopathic brains were functioning as if they had been asked to work out an algebra problem. Conclusion: sociopathy involves an altered level of processing of emotional stimuli in the cerebral cortex (as compared to non-sociopathic brains), although the reason for this is not yet clear. It may be the result of a heritable neurodevelopmental difference that can either be slightly compensated for, or made much worse, by cultural, environmental, or child-rearing factors. If you are interested in learning more about this topic, you may want to read Stout's book entitled The Sociopath Next Door.