I was looking at this article which suggests that socializing can increase thinking ability and exercise the mind. Regular social interaction is certainly a basic emotional need but of course it does depend on who you hang out with. We tend to become more like the people we are with; in fact to an amazing sometimes frightening degree-see Suggestibility: How to be an Einstein

If you are lucky enough to have stimulating, intelligent and fun friends then I reckon they will definitely help keep your mind active and strong.

Ah well often to my Mensa meeting (just kidding )

Mark