Watching cable news is not for the young. A new Nielsen survey shows Fox News has the oldest audience, averaging 65 years of age. CNN was right behind Fox, with a median audience age of 63, followed by MSNBC (59) and CNBC (52). The same survey showed that those who tune into network programming tend to be middle-aged, with CBS’ median viewership being 55 last season. ABC’s audience came in at 51 and NBC at 49. Fox’s network audience, helped by such programming as its animated comedy block, has a median primetime viewer age of 44. The youngest of the networks is CW at 33, which is not surprising since its target audience is women aged 18-34.