I have been thinking about the "cause-and-effect" phenomenon in the social context. Simply put, an event-A happens, which causes or triggers event-B. Newton's Third Law (Every action has an equal and opposite reaction.) can be explained in laymen's term as: Every action has consequences. Interestingly, the Hindu philosophy takes this scientific rule and apply it to everyday life. The laws of karma imply that your current living conditions (good or bad) are actually caused by your karma (deeds, or actions) from your early life or even from your previous birth.
The situation that interests me particularly is: Cause (Event A) --> Effect (Event B) --> Cause (Event A). In other words, Action-A triggers Action-B. But then Action-B becomes trigger for Action-A. The consequence reinforces the original cause. And the wheel can keep turning forever.
I can think of a hypothetical example of a husband and wife. The husband thinks that his wife is not treating him with respect (Event A). Disappointed, he starts drinking and coming home late every day (Event B). But this just makes things worse, and his wife now actually disrespects him (Event A, again). Once this kind of rather vicious cycle is in motion, it becomes impossible to tell where exactly it started. Did the wife not treat her husband well in the beginning? Or was it just a wrong assumption on the husband's part?
Other examples comes to mind. A minority group in a society finds it difficult to get jobs in spite of having a good level of education (being discriminated and all). So they become less interested in getting college degrees and more involved with petty jobs and joining street gangs and criminal activities. This reinforces the majority group's discriminatory feelings towards the minority. Which, in turn, makes it more difficult for minority folks to get a job. And the vicious cycle continues!
Let's say you hear somewhere that road accidents are more likely to happen when you change lanes. So you try to be extra careful while changing lanes. This wavers your normal driving sense, and you become more likely to make a mistake. An accident happens. And this validates your initial belief (which might not have been true to begin with!).
These example are also related to a phenomenon called "Self fulfilling prophecy". As explained by the Thomas Theorem:
"If men defined situations as real, they are real in their consequences."
Take the story of Krishna for example. The king of Mathura, Kansa, hears a prophecy that he will be killed by his sister Devaki's son. So he puts her behind bars and plans to kill all her sons. (Don't ask me why he put both Devaki and Vasudeva in the same cell!) So Kansa kills Devaki's first six children. But the seventh (or was it 8th?) child Krishna was smuggled out of the prison. And eventually, Krishna grows up to kill Kansa. End of story. Now the question is: Was Kansa's death bound to happen by Krishna? or was it Kansa's attempts to prevent the prophecy that actually led to Krishna's birth who eventually killed him?
By the way, isn't Lord Voldermort and Harry Potter's story is somewhat similar to Kansa and Krishna's? Both have similar prophecy of antagonist's death, and the opposing characters have blood relationships.