While observing correlation may be a good starting point to investigate possible causation, it does not automatically mean there definitely is causation. This is important to know because much of the rhetoric we hear every day from the media, politicians and other agents of influence exploit this misunderstanding to further their agenda.
Check out this learnist board for a host of simple explanations and useful infographics posters and articles discussing the difference between correlation and causation.
To minimize such errors in your arguments, it might be useful for you to consider the involvement of mediating variables in your points rather than to simply lay down simplistic causations in your essays (e.g. more video games = more violence; more social media users = more friends). When comparing a writer that suggests correlations that may imply causation versus a writer that simply assumes a causation, the former obviously will come across as more objective, balanced and mature. Compare the two arguments below:
1. Violent video games are harmful for children because they provoke aggressive behavior in them.
2. Violent video games may be harmful for children because they may increase the risk of aggressive behavior in them, especially if they have been influenced by violence in other sources like the media or even their own social environment.
Both arguments try to suggest a relationship between the two, but the second one is more moderated in acknowledging that the causation is not so straightforward I know the example is pretty simplistic (sorry!) given the huge amount of research in this area but basically, you get the point right?