Also, I would be curious what the definition of social intelligence is. I don't think my layman definition would fit into the way it's being described above.
Currently, there is no dominating definiton of social intelligence within social sciences. A simple way of explaining the meaning of the notion would be to say that people with a high social intelligence has good "people skills". However, a person with a high social intelligence should not only be good to interact with other people himself/herself, the person should also be able to help people he or she is interacting with to achieve better relationships with each other.
Several conceptualizations exists and how you define social intelligence will be different within different philosophies of science and even within the same paradigms and schools of thought one might find conflicting definitions.. However, when working with subjects such as this I often take a relational responsive approach developed within social constructionism inspired by an intersubjective ontology. In this perspective social intelligence will be related to the relationship between people and how good you are to make a relationship mutually beneficial for both you and the ones you are interacting with instead of thinking of yourself only. Social intelligence is also influenced by how good you are to read other people and get a feeling and understanding of how they feel. A high social intelligence will make you very susceptible to the feelings of other persons, thus making you very good at emphasizing with other people and their situation. You will also be good at communicating with others and make other people better at communicating as well. But before you can excel at understanding how other people feel you need an emotional intelligence of your own so you can understand your own feelings as well and posses self-insight and the ability to be reflexive and to reflect. People with high social intelligence can for instance be beneficial to place in a department within an organizations that is not currently functional due to arguments and generally irrational behavior. Here the person will be able to identify the reasons why the people making up the group have problems working together and identify whom have had their feelings hurt in the group and why and whether this is an overreaction or not as well as identify people that might actively be attempting to sabotage the department by wreaking havoc and chaos. To stop the trouble-maker the person with a high social intelligence might first attempt to identify the feelings and reasons that are causing the trouble-maker to behave as he does and see if it is possible to help the trouble-maker and make him feel better and thus integrate him better in the group by appealing to his emotions combined with rational arguments explaining why it might be better for the trouble-maker to stop the behavior that causes troubles and what he in turn will gain from this.
If you are intersted in reading more about social intelligence within the same philosophy I mentioned you could take a look at books like Narcissistic Behavior in the Postmodern Era: The Study of Neuropsychology by Rudolph Hall and Social Intelligence: The New Science of Human Relationships by Rudolph Hall. These are okay books, but not excellent. However, the best books I can refer you too will require a deeper understanding of the differences between modernism and postmodernism within social sciences and a good understanding of social constructionism. Kenneth Gergen would be a good place to start if you with to understand this particular kind of social constructionism I am referring to. However, this is scientific books and will make no sense to people without an academic background within such disciplines as anthropology, philosophy, sociology, economics and business administration, psychology et cetera.
However, I think books exist that are more readily available to people without a background in social sciences who are interested in emotional and social intelligence and how you can use them to get a better life by gaining more self-insight. Now I start to sound like somekind of life coach and I definitely not want that

But for addicts and people with psychological problems, reading about emotion and social intelligence might be helpful in terms of getting a better life. Though it is no guarantee as I am evidence of

You may know every theory known to man within social sciences and still end up as an addict with severe psychological problems

One benefit though, is that I can have fun experimenting with therapists et cetera and see if I can act in a way that will make them give me a diagnosis that is completely wrong. This might be juvenile and dangerous behavior, but hey, a scientific experiment is a scientific experiment
This page
https://www.karlalbrecht.com/siprofile/siprofiletheory.htm and this page
https://en.wikipedia.org/wiki/Social_intelligence can be used as a quick introduction.
While searching for more pages that a layman might be able to benefit from I found some page that are specifically about addiction and social intelligence
https://www.researchgate.net/publication/233978774_Social_intelligence_indicators_for_addiction_disorder_patients
https://www.addiction-ssa.org/symposium/presentation/changes-of-indicators-of-social-intelligence-for-substance-use-disorder-pat
http://agris.fao.org/agris-search/search.do?recordID=LV2012000629
However, I havn't looked closely at any of the links or read them yet. I will have to do that before I can assess the quality of the pages. I will do this later, but they might be interesting and helpful