An interesting thing about marriage is that no matter who earns wages it is ultimately an economic partnership.<p>Someone must keep the living space clean, someone must obtain food, etc. If there are children, someone must care for them.<p>Because of this, when marriage is freely chosen, it typically starts out as equal.  Both participants have roughly equal costs and benefits, and are both happy with the exchange of value.<p>But time changes things.  Wages often increase, looks often decline, personalities evolve.  Profound setbacks occur as loved ones get sick or die, careers suffer failures and successes, etc.<p>Most people are morally average, of average attractiveness and average intellect.  Most have an average work ethic, average level of discipline, and average level of fortitude.<p>Life stretches most people beyond their endowment in many areas.  We lie or deceive, we get lazy, we get complacent, we give up, we cheat, we fail to observe data without significant and harmful bias, we let life happen, our faces take on a habitual grimace that becomes permanent as our skin&#x27;s elasticity diminishes.<p>For a marriage to work long term it must be resilient to this abundant averageness and the inevitable decay that occurs over time...  when the weak or neglected parts of the mechanism start to falter.<p>The question is, should a marriage work long term? Is it a failure when it does not?  What if it lasts 10 years, or 20, or even 5?  Should it not have occurred?<p>We marry because we are the primates with dogged optimism about pair bonds.  We seek another who will provide us with the validation or the comfort that we seek, and who will dull the harshness of the world in some specific way that we consider most wanting and most sacred.<p>Even the gay marriage debate, for all the focus on equality, is fundamentally about the symbolism of the pair bond and its primacy in our primate society. We are herd animals, and the minimum viable herd size is two.