Somewhere between the two myths of the "noble savage" and "civilization is the thin crust on a volcano" lies human nature. Unfortunately, strategies based on force and deception are hard-wired into our monkey brains, and will always need to be controlled. Fortunately, counter-strategies are also built in. While extremes of human behavior can occur (Victorian virtues, ethnic cleansing), human nature pulls society toward an equilibrium somewhere in between, probably more toward social harmony. The glue that holds society together is altruism, which comes in two flavors: kin and reciprocal. It is not a good thing that in modern times bonds of kinship have weakened as people have fewer children who move further from home. Large, anonymous cities do not foster the reputational record-keeping conducive to reciprocal altruism.

Long before he penned the book that justified laissez faire capitalism, Adam Smith became the first evolutionary psychologist when he observed that "Nature, when she formed man for society, endowed him with an original desire to please, and an original aversion to  offend his brethren. She taught him to feel pleasure in their favorable, and pain in their unfavorable regard." --Michael Shermer

On the other hand, modern communications technologies, like the telephone, the Internet, and personal address databases, increase ties between people, and certainly a credit rating is a reputation that will follow someone from city to city.... While it is risky to try to twist evolutionary psychology to an agenda (feminists and social darwinists have tried and failed), EP does provide evidence that the human animal does have hard-wired mechanisms that foster living in a society without the need for complex, rigid laws imposed from above. We're network-ready, right out of the box.

I. The Altruism Instincts

1. Kin Altruism: Family Values

   Mutual assistance between blood (i.e. gene-sharing) relations is the oldest form of altruism, and the strongest ("blood is thicker than water"). This suggests 90+% of parents can be expected to do right by their children, or at least to do better by them than strangers would. Outside interference in a child's education or medical treatment will not be justifiable 99% of the time, and the exceptions should not justify interfering with the majority. Parental investment is a strong human instinct, and the best that the government can do is to get out of the way, or at least to set policies that strengthen existing bonds (e.g. make wayward fathers support their children) rather than weakening them (e.g. supporting unwed mothers). The same goes for welfare and unemployment benefits: strong families support their members; government's taking up this role weakens families bonds.

2. Reciprocal Altruism: Contract-Making

   A handful of animals--at least the chimpanzee, dolphin, and vampire bat--do each other favors, and then expect future payment. These animals are also unusual in that they have relatively large brains, leading biologists to suspect that brain enlargement is at least partially due to the demands of keeping track of who owes what to whom, and who is reliable and who is not--in short, reputation. If the human animal is also wired to make and enforce contracts, that instinct should be relied upon, and indeed contract is the basis of commerce and trade is a cultural universal.

3. Gift-Giving: Charity

   Man has a hard-wired instinct to maintain reputation through gift-giving. In the old days, and in some societies to this day, a fortunate hunter shared his kill with the tribe, not just with his family. The rise in his status or reputation was like money in the bank, which he could then cash in for favors at a later date. This instinct can be relied upon to support charity, provided that reputational record-keeping is in place. Anonymous donations are noble but rare; people will contribute to the church collection plate, in full view of everyone else. Check out this list of on-line charity resources.

II. The Fairness Instincts

People can employ several negative strategies that roughly correspond with the altruism instincts, and we have therefore evolved defensive instincts to counter them. These fairness instincts universally evoke a sense of outrage and righteous indignation, eventually leading one to feel justified in using force, or at least shunning the offender.

1. Counter-Parasitism

   Some people are very clever about finding ways to take more resources than they give, either discreetly or with some sort of justification ("My leg hurts--you go hunting today, and I'll stay at the camp and guard the women."). The parasite strategy evokes a mild counter-parasite response that only builds slowly over time. Right-wing tendencies to support "family values" and fend off free-loaders may derive from this instinct.

2. Cheater-Detection

   Human beings have a particular sensitivity to situations where someone is breaking a contract, i.e. cheating, and this provokes a particularly strong response, supported by feelings of righteous indignation. Libertarian tendencies to permit any act (and enforce any contract) between consenting adults are supported by this instinct.

3. Counter-Dominance

   Some psychologists theorize that there exists a counter-dominance instinct that leads to resentment or even violence against a greedy wealthy person. This has its origins back in the hunter-gatherer days, when a successful hunter with a kill would bring back more meat than he could eat, and sharing bought him goodwill and increased status from the other tribe members. Any one man, no matter how strong or successful, would still be subject to violence from a coalition of weaker men, or even one weaker man waiting for the proper moment for an ambush. Left-wing "politics of envy" may derive from this instinct.

   You can read about the counter-dominance instinct in the article Injustice, Inequality and Evolutionary Psychology by Bruce Charlton, and in this game-theoretic explanation of how people demand their 'fair share'.

III. Reputation and Gossip

Reputation is how we keep score of who is contributing how much, or taking how much; gossip is how we communicate it. We have a tendency to spread negative gossip more than positive, probably because negative gossip, by lowering one person's reputation, increases the speaker's reputation. Modern technology greatly enhances our ability to track people and their reputations (hence the resistance movements toward "personal data protection" and a "right to privacy"), e.g. credit reports and other databases.

IV. Coercive Arguments

Those who argue for coercive solutions to society's problems justify themselves by claiming some sort of "failure" in the market or human nature, e.g. modern cities are too anonymous to engender altruism; modern families are too weak to rely on to care for children, the elderly, or the disabled; profit-obsessed businesses have interests unaligned with those of society, etc. Leaving aside the morality of coercion, it is unlikely that centralized government solutions, still subject to the weaknesses of human nature but devoid of the fairness instincts that are active only at a local community level, would be any better. In fact, it is more likely that the proposed coercive solutions are disguised parasitism, however noble the expressed justification, and should therefore be firmly resisted.

In summary, we should rely on our nature where it supports moral acts or inhibits immoral acts, and focus on discouraging negative, force-based strategies that are built into our natures.