With social contacts I mean your contacts with other people, either intense or very shallow. So how do you socialize with your family, your husband or wife, your children, your best friends, your acquaintances, your colleagues at work, and other people you sometimes have to deal with?
Your brain has to function properly to maintain an adequate and friendly network of contacts. It seems so simple but you need your memory to remember what a friend has told you, or to remember an important appointment with him. In conversations it is important to remember what you are talking about, to remember what your friend is talking about so you can ask the right questions at the right time. Just imagine how annoying it is when your friend keeps asking the same questions again and again in one conversation. And precisely that is happening when someone has Alzheimer's disease. A contact becomes annoying or boring when your partner has serious memory problems.
Furthermore, you'll need adequate vision and hearing capacities to communicate without much irritation. You'll probably have experienced once how difficult (and irritating) it is to shout to someone who doesn't have his hearing aid on. That vision is important in social contacts seems quite logical. But what most people don't know is that vision on a higher level is required as well. By that I mean that the brain has to notice very subtle nonverbal communication signs in a conversation. The way someone blinks, the way the eyebrows move, the way the mouth or face changes, all these things have to be processed to interpret someone's intentions. Now, there is a large variability in brains that can do this. Most people have not really trained these abilities and what they don't realize, they are not really good at this. The consequences are that they don't interpret someone else's intentions correctly, leading to small (or large) miscommunication. For example, interpreting someone's emotions by 'reading his face' is very difficult. Just do a test you can find on the Internet in interpreting facial images, then you'll see how hard this task is.
In the same way, hearing is that much important. You'll need to hear the very subtle tone differences in a human voice that indicate how something is feeling (and thinking). Just as in reading a face, reading a voice is extremely difficult. Only people trained for this and with a natural talent can do it perfectly (like professional singers). The brain has to interpret the changes in voice volume and its speed, in order to understand how someone is feeling or thinking. As a psychologist I will not pretend to be perfect in this but I know I can (and have to)do this much better than other people do. In my youth I trained my brain by looking and listening carefully to birds (don't laugh). That gave me an advantage over other people not trained like this. Of course, back then I didn't do it intentionally to become a psychologist (I was 10 at that time). But surely, my brain regions involved in interpreting sounds and forms, did grew in their capacities by (just) my bird watching for a couple of years.
Maintaining social contacts require the highest brain functions, the so-called executive or regulative functions. On another page about Tests I'll explain much more about these functions. For now, I can tell you that the main components are planning and organizing, seeing your own mistakes and correcting them.
Planning and organizing? Yes. In maintaining your contacts you need to think of and about your friends' interests, their wishes and their sorrows. You'll need to think of how to care for these things, you'll actually have to 'make a plan' for how you support your friends. The word 'plan' sounds a bit strange but it actually is a plan: a schema, a more or less organized bundle of ideas in your mind how you want to do some things for your friends. The way you invite them, what you'll buy for them when they visit you, what to do with them when you are out with them. All these things are made up in your mind, your brain has made a 'plan' or 'script' for this, largely unconsciously (more or less automatically). But this planning can be damaged by a brain injury, and worse, this kind of planning is not the same in every brain. There are people who are not that good in planning these kind of things. They are seen as 'less attentive', less 'social'. A very clear example are the more autistic persons. Yes, it is not only emotions that count in social contacts. It is also a 'technical' thing: you have to be able to plan adequately.
Another executive part of the brain is seeing your own faults and behavior and evaluating it. The brain has a module that constantly monitors your own actions, either being movements, your talking or your social actions. When this module does not work optimally, for example when you're drunk, your behavior can be inadequate, 'way off line', crossing the line. That can have serious consequences, especially in your work. The famous case of Phineas Gage, who suffered serious prefrontal damage, shows his behavioral changes in social aspects and he couldn't keep his job. Being able to see when and how you have gone too far in your social behavior is not only an emotional thing, it is also very technical. You have to know certain social rules, you have to see clearly your own actions and you have to see whether your actions differ too much from what is accepted or not. Of course, your emotional brain has to play a part as well. In a real sociopath (formerly called 'psychopath'), the emotion like anxiety or sadness is less intense so they can react quite differently than we do without understanding that what they do can be shocking to others. They really don't 'see' their social mistakes, that is why treating them is so difficult or even impossible.
Finally, faulty behavior should be corrected. But this can only happen whenever you really see your mistakes at the first place. Why would there be any motivation at all to change your behavior when you absolutely don't see what you are doing wrong? And you should be creative enough to find an alternative way to behave when you have seen your mistakes. That involves planning again and certainly some flexibility.
In telling you this I hope you will realize that maintaining your social contacts isn't that simple as you always thought. Your brain has to really function in optimal condition to do it right. Of course, for some it comes easy: their brains probably have had a lot of training or are genetically prepared for the above mentioned functions. But for most people, keeping their social contacts in good shape, requires a lot from their brains. Normally, they do not know that, unfortunately. And just that is the reason that there are large differences in people who easily manage to have nice social contacts, and others who really struggle with it.
The positive thing about it is, that you can train these functions to improve your social functioning, up to a certain point. But you'll need a coach who is really good, authentic and honest. Cheap, superficial coaching can lead to the same quality of social functioning. Of course, when a lot of people are that bad in social contacts, they don't notice it between each other. But I do, and probably you too. And then you'll remember my story here: their brains just do not function optimally...;)