TV is no longer the dominant screen in British living rooms

"Myth 1: TV is the dominant living room screen and entertainment the dominant activity
Only 50% of UK online adults now say the TV set is the focal point of their living room, whilst 70% report they ordinarily use a connected device whilst watching TV – this rises to 87% of 16-34s. Multi device activity peaks between 6-9pm.
During TV programmes, over one third (34%) check emails, 31% Instant Message or text and 25% shop online.
The biometric data revealed that about 60% of the time a person is most highly engaged during an evening TV session is in non-TV related activity, such as using a digital device or talking to someone.
“Second screening is ingrained to such a degree that all screens are now equal, there’s no hierarchy, only fragmentation of attention – actually switch-screening is a much more accurate term,” says Tim Elkington, the IAB’s Chief Strategy Officer. “Furthermore, entertainment is only a small part of the living room media activity. It’s now a multifunctional space where people jump between individual and group activities, be it shopping, social media, emails, work or messaging.”
Myth 2: TV programmes and ad breaks determine behaviour
The study revealed the traditional assumption that people cram non-TV related behaviour into the ad breaks is no longer valid.  
For example, the incidence of checking emails is consistent during TV programmes and ad breaks (both 34%) whilst texting or Instant Messaging is only 1% higher during the ad break than the programme. The device tracking showed, overall, there was actually more online activity per minute during a programme than an ad break.
Furthermore, the declining “kettle power surge” during ad breaks in peak TV occasions over the last 25 years provides more evidence of the change in the traditional rhythm of the living room. During the biggest TV event in 1990 – England’s World Cup semi-final against West Germany – National Grid data compiled by British Gas shows a power surge equivalent to 1.12 million kettles boiling at the same time immediately after the match. In 2014’s biggest TV event – England’s World Cup match against Uruguay – the power surge was the equivalent of only 410,000 boiling kettles."

Source:  IAB UK, 11th February 2016