There has been a lot of talk in the past decades about income inequality and for good reason. Various factors contribute to income inequality, such as the political orientation of a country or its economic status. But at the root of unfair reward systems lies a way of thinking that associates people with the immediate economic benefit that they bring to a group. In other words: no long-term strategy.
Such reasoning made more sense in a past when a famine could threaten the survival of an entire culture. Even though we live in quite different times (many countries are approaching post-scarcity economy), our instinct hasn’t quite caught up yet. This is not entirely surprising given how fast we’ve evolved in the past centuries. Our “firmware” hasn’t had enough time to adapt. So, we’re still prone to terribly pragmatic and survivalist decision-making. Social contribution inequality is the result of this style of thinking. It is the poor rewarding of some members of society because others do not immediately see them as being profitable.