As the young brain learns, it does so by repeatedly traveling down a path. With advanced age, the paths drop out. Such a shrinkage of paths in the brain offers an explanation for the repetitive and ingrained habits seen in the elderly. Neurochemically, pleasure is actually very closely linked to stress or pain. Anytime we experience these sensations, our brain produces chemicals known as endorphins.
Endorphins are addictive, especially over time.
Further implications However, the ball doesn't stop rolling here. A recent U.S. study, which has subsequently been repeated in several centers, compared 21 murderers on death row with 21 normal subjects. All participants were subjected to an extensive neurological exam. With today's plethora of research, modern neuroscientists are beginning to recognize that crime, at least the most serious crime, seems to need an anatomic abnormality in the brain in order to happen, with the remainder of the recipe coming from events in the individual's background. This has startling implications, implications which are already being discussed not just by philosophers, but by workers in the criminal justice system.