The data comes from online surveys of 2,086 people aged 18 to 55 for YouGov's social TV trends report, which was commissioned by social media agency Diffusion.
The habit, which Diffusion refers to as "media stacking", although it does not claim to have coined the phrase, describes the behaviour of consumers who use Facebook on their laptops, send text messages on their mobiles and listen to the radio, at the same time as watching TV.
It found that the habit is becoming normal practice and is particularly prevalent among 18- to 24-year-olds, with 76% saying they "regularly" browsed the internet while watching TV.
Social networking sites are the most common distraction, with 40% of female TV viewers updating their profiles while watching TV, compared to 29% of men.
Almost half of all adults and 86% of 18- to 24-year-olds said they had used channels such as mobile SMS, Facebook or instant messenger to discuss what they were watching.
With TV and the internet set to converge further with new-generation TV sets, the report also asked consumers which websites they would most like to have access to through their TVs.
Google was the most popular site, with 28% stating they would like to access the search engine.
A quarter of those surveyed said they would like to access online retail sites such as Amazon and Asos via their TV sets while watching programming. A similar percentage (26%) would also like to be able to access social networking sites like Facebook and Twitter.
Just more than one in 10 adults claimed to use a video games console while watching TV content.