Toni ... some quick thoughts about prisons and prisoners.
"Differentiation" occurs by varied means; so does cooperation. Molecules have rules, so do mothers -- both molecular rules and morality control working relationships, upgrading or down-regulating them as a consequence of resources and output. Living cells build walls but they also arrange to take in and to eject materials. Likewise for people. Restrictions to interactions come in many forms -- social rejection from the school dance, placement in an alternative school program, or prisons. Groups have mechanisms for rejecting members when there is a failure of reciprocity. Prison is one of them. Other mechanisms have been enrollment in the military, eviction from school, forced emigration, elaboration of social classes, and building of walls around our homes and businesses.
Blame a culture ... the Southern "gentlemen" Scotch Irish and herders. High proportion in our military. High proportion will forgive an insult more quickly than a sneak attack (Nisbett, HBES, July 1998).
Blame an allele ... the D2A1 is differentially distributed globally and occurs least frequently in groups presumed to be "hunters" whereas "farmers" tend to have a higher percentage of D2A2. D2A1 (unless I have them backwards) tends to be associated with more greater alcohol sensitivity and gambling problems. D2A2 tends to be associated with planning, less impulsiveness, and perhaps more strategic behavior.
Blame temporal lobe dysfunction ... mild temporal seizures are correlated with heightened verbal output, increased sexual interest, heightened religiosity, excessive attempts at dominance, excess self esteem, and a grandiosity that the rules "don't apply to me." These traits are commonly found in mania and bipolar disorder. The "rules don't apply to me" is also characteristic of sociopathy and may be associated with an excess availability of serotonin. (There are plenty of other considerations -- some of these people are jailed, others build skyscrapers, put in superhighways, lead us in war, or become President. Oh yes, lying is not an unusual tactic as with most of us; it's just the lies are more clever or have larger consequences.)
Blame lead ... Masters (Dartmouth) spoke about differential distribution of elevated lead in humans, correlated not with lead in the air but with water fluoridation options, one of which causes a differential uptake and retention of lead. Rome went down with lead, we might as well.
Blame absent fathers and low parental investment for predatory behavior ... children without consistent parenting appear to become more "feral," less dependable, and more immediately self-interested.
Blame intellectual impairment ... the figures for mental retardation and various learning disabilities are quite high in prison populations.
You can "tell" and "give reasons"; however, complexity theory, behavior modification, psychological adaptations, and any number of other models imply that "habilitation" may depend on (1) finding places where the individual's liabilities become assets, (2) frequent monitoring if you can't do (1), consequences that are immediate, certain, and personally relevant, and as pharmacology moves along -- certain classes of medication, including some that cut into self-esteem. An essential step could be that of removing the individual from the setting wherein he gets in trouble -- because of friends, opportunity to inflict harm, lack of gainful opportunities, etc. -- and moving him to a different one. Again, "complexity" factors get in the way. EP offers a summary of adaptations that probably work; it may give some hints about some of them -- "the reciprocity regulators" -- that don't work. I'm not sure we have "repair" capability as yet beyond the suggestions that I just offered. Until we DO have some effective methods, then we will have to use prisons.
NOTE: "Complexity" here refers to a telephone pole I witnessed after a storm. The pole was broken in half but still erect, supported by 12 tension lines attached to the cross members. Likewise for us ... we are "held" in place by our kids, our pets, our magazine subscriptions, our mortgates, and so forth. People in trouble have similar constraints that lead them back into trouble. Incidentally, some of the "blames" above are associated with features that resist personal change -- doctors and judges, teachers and restrictive parents are all targets for resistance. The intense self-determination that can lead to criminal action will also lead many of those in prison to reject absolutely any efforts to make a significant change in their attitudes and values. Ironically, many of these folks have a self-sense of tremendous "free will" and may "use" helplessness as a tool.