Contingency plays a massive part in social events, indeed in all kinds of events not just our lives; that is why we can tell its important in our lives.
We rarely control the outcomes of much activity, and we interact with situations that we do not cause and cannot influence much, but do influence some little bit. There are important choices we make, and we may not realise how important they were until we look back on them. At the time the choices may have seemed trivial – going to a particular party, leaving to urinate at a particular time, turning our eyes away from the road, not responding to a phone call, being ill at a particular time. This sort of contingency can affect whole countries, as it affects people who make decisions. We might call it the “for want of a nail effect”, given the famous verse.
Contingency also affects the coming together of different events at specific time, such as an infrastructure failure compounded by economic crisis and a drought, even if we may say that certain behaviours and policies make this contingency more likely. The effect of the contingent combination may not be predictable – how will people respond? It is exceedingly difficult to see, in advance, how fortuitous circumstances will allow particular social groups to gain an influence that they previously did not have because the new circumstances ‘obviously’ favoured them over others (in hindsight). Any kind of evolution is contingent on circumstances, even if organisms are not controlled by circumstances.
I’d suggest being skeptical about any non effect of ‘luck’ in social life. The idea that luck is not important is a very convenient ideology for those who are wealthy because it implies that they are were they are, totally because of their abilities and skills, and are thus justified in having wealth while others don’t. While if success involve luck then they are were they are by luck as well as by skill.
Complexity theory implies that we are incapable of predicting events in detail, although we can predict general trends, because of the massive interconnection of things/events and feedback between things and events. Thus we may predict the decline of the US under the pressures of successful capitalist domination, but we could not predict how it will turn out. In 2010 we could not really have predicted the rise of Trump and his cronies. Whether this unpredictability stems from the human inability to model things completely outside the system itself (so while we cannot predict specific events, if an all knowing God exists then that God may be able to predict successfully), or because it is in the nature of the system (even an all knowing God cannot predict specific events), is irrelevant for human contingency.
Because of unpredictability and complexity we always contend with unintended effects, some of which may be good, but probably more will appear to be complications – as the number of patterns which seem disordered is far greater than those that seem ordered and beneficial. Social life is precisely about dealing with the unexpected, as well as the expected. Often people deal with the unexpected by pretending it has not happened. This retains the vision of order, but weakens people’s ability to deal with reality. The unconscious has a tendency to strike back.
The importance of contingency does not mean analysis is impossible, but it does mean that we need to factor in contingency as part of that analysis, and look at rare events rather than be remain happy with what appears to be common. This is particularly so when we appear to be entering a realm, the Anthropocene, where we have no prior experience whatsoever.