• by Wayne Friedman , October 5, 2010

After two weeks of the new season, the broadcast networks have all aged a bit. 

The big four all witnessed their higher median ages versus the first two weeks of the season a year ago. CBS is still the leader, with a median age of 55.6 years old -- up one-tenth of a year, according to Nielsen from a Horizon Media report.

ABC grew half a year to 53.1. NBC went up two-tenths to 49.5. Fox -- still the youngest among the big four at 42.6 -- also grew half a year. (The CW was not included in this report.)

The oldest network show, again, was CBS "60 Minutes" at 60.2. It actually got a bit younger, from 60.6 a year ago. Among its regularly scheduled shows, CBS' "CSI:NY" was next at 59.5. CBS only had two shows under 50 years old: "Rules of Engagement" at 48.8; and "How I Met Your Mother" at 47.8.

ABC's "Dancing with the Stars" performance and results shows were the network's oldest-skewing series, at 56.5 and 56.9 years, respectively. On the flip side, the network's two Wednesday comedies -- "Modern Family" and Cougar Town" -- were the youngest, at 47.7 each. The canceled "My Generation," about the travails of college graduates, had a median age of 51.8.

NBC's youngest show was "30 Rock" at 42.3. The network's oldest -skewing series included its new show "The Event," averaging 58.5. "Dateline Friday" was the oldest, at 59.1.

With its Sunday comedies, Fox comes in well under the older network -- almost six years younger than NBC. The "Family Guy" median age was the youngest at 29.7 -- and the youngest among the top four networks. "American Dad" was next at 30.5. The oldest shows on Fox were "Bones (55.4) and "Human Target" (56.1).