Young people aren’t watching TV live as much as they used to, but you already knew that. What’s particularly interesting about the habits of Gen Y TV viewers, those age 13 to 32, is that 12% are now watching streaming video on their TVs during primetime, up from none four years ago. This age range is 30% less likely to watch a TV network during the 8 pm hour than they were four years ago, according to a just-released study from research firm GfK analyzing primetime habits over the last several years. Specifically, 57% of TV viewers in this segment are watching TV live at that time, down from 82% in 2008. Instead, they are watching programming when and how they want because 28% of viewers in this group are watching recorded shows during that primetime hour, up from 15% four years ago. Among Gen X TV viewers, from age 33 to 46, about 3% are watching streaming video on their TV sets in the 8 pm hour. In the 18 to 49 group as a whole, 7% are streaming videos on their set during primetime. But the habits of the youngest group are most noteworthy because they provide directional insight as to where consumer behavior is headed in the coming years. Streaming video on the TV doesn’t necessarily equate to viral videos or Web series. In many cases, viewers may be streaming TV shows via Netflix, or renting programming on iTunes or Amazon. Nevertheless, the increased usage underscores that broadband video is converging with the TV set for the younger generation. The biggest challenge for TV networks will in the impact these changes have on ad dollars in their primetime audience, Gfk said. The study draws from GfK’s surveys and research on media usage.