IT'S called 'retro-reality' and it is all very Year 2000. On one TV show, a group cut off from the modern world have to build society from scratch in a remote location in Scotland, surviving for a year by growing their own vegetables and killing their own animals. Switch over to another channel and viewers can watch a gaggle of fairly tawdry strangers trapped in a house together for weeks on end, battling not to be evicted by public vote and emerge victorious in the popularity stakes.

We are 16 years on from the first reality shows which captured the public imagination - Castaway 2000, set on a Taransay, and the very first series of Big Brother - but if the current crop of reality TV shows on our screens seem pretty familiar that's because they are part of the latest trend in television: retro-reality, or to put it another way, lazy producers stealing ideas from earlier decades.

Last week another set of new Z-list contestants entered the house for Channel 5's Celebrity Big Brother, while Channel 4's screened the latest episode of Eden, billed as a ground-breaking social experiment in which 23 men and women will live for a year cut off from society in a remote estate on the Ardnamurchan peninsula. The group have been given limited supplies to start but will have to grow their own crops, raise livestock, fish and construct living buildings from scratch.

In the first two episodes, the challenges for the Eden inhabitants have included living on a diet of endless potatoes, struggles to catch fish and disputes over the priorities needed to survive: build a tepee for group meetings or grow some vegetables?

Eden has been mocked for scenes showing the group eating gnocchi and growing kale. “It’s so middle-class why don’t they build a Waitrose?” went the comments on Twitter. Channel 4 insists it is not intended to be a survival show, but about building a community from scratch.

The first episode of Eden was seen by 1.8 million viewers, a healthy audience for a Channel 4 show. Last week’s launch of Channel 5’s latest series of Celebrity Big Brother was watched by an average of 2.3 million viewers.

Those figures are a far cry from the days when an audience of 10 million tuned in to watch Craig Phillips win the first series of Big Brother, or Castaway, which drew audiences of around six million on BBC One.

Annette Hill, professor of media and communication at Lund University, Sweden, and author of a series of books on reality TV, said certain elements of the reality TV show genre were suffering from fatigue, such as talent shows and competitive reality shows.

“The reality genre always has to reinvent itself pretty fast – it is fresh one minute and then it is yesterday’s news," she said. "Making it more extreme or more of a spectacle is one of the ways reality TV has gone.

“Then the other way has been to become more gentle and sweet again. Gogglebox, for example.”

Hill said Eden had echoes of the series Castaway, in which 36 women, men and children lived for a year on the island of Taransay.

She said this “retro-reality” concept was one way of trying to refresh the reality TV genre.

“The fascinating thing about Castaway as it came out at the same time as Big Brother,” she said. “You had the observational style going on in that show, but then the competitive reality show (Big Brother) took over.”

Behavioural psychologist Jo Hemmings, who specialises in the media and celebrity analysis, said reality shows with a ‘survival’ element had particular fascination for viewers around relationships and surviving in a world which is far removed from comfortable modern day living.

“It is very unscripted, they are pushed to their limits, and it tests group dynamics, individuals, tempers and romance – they are in a very challenging environment and it is about how they sink or swim,” she said.

“It is different to other reality TV shows as it is not like you are voting for people to stay on, it is not like it is a popularity contest.

“On Big Brother they complain when they are on rations for two days or that the electricity has gone off and how will they use hair straighteners - I think watching something which is really demanding of most people has always fascinated as it is so very different from a world that we can imagine living in.”

Hemmings said that with the rise of technology such as mobile phones and social media, the idea of being cut off from the world – as the group in Eden are – would have even more of a shock impact now for younger generations.

“In the last decade we are starting to live in a much more virtual world than we ever did," she said. "The further we get into our pampered world, there is the shock or fascination factor. For younger people it is like they can’t even believe that anyone lived like that.”

With the rise of reality TV since 2000, has come the rise of the reality TV ‘personalities’, who populate an endless succession of magazines and gossip columns.

Many of the 15 celebrities in the Big Brother series launched last week are that curious 21st century phenomenon: reality show contestants who are famous for being on previous reality shows - an extension of the 'retro-reality' trend. They include former X-Factor contestants Chloe Khan and Katie Waissel, Lewis Bloor, who has appeared on The Only Way is Essex (Towie), Marnie Simpson from Geordie Shore and Renee Graziano, part of the Mob Wives TV show in America.

In contrast Eden is populated by a host of members of the public – for now, unknowns - who have been selected for their skills. The group of 23 men and women, mainly in their 20s and 30s, include junior doctor Jenna, shepherdess Caroline, trainee yoga instructor Jasmine, gamekeeper Glenn, former army officer Jack and vet Robert.

Back in 2000, the Castaway series turned into a launch pad for participant Ben Fogle’s television career, while Big Brother has become known as a magnet to those aspiring to join the world of Z-list celebrities.

Dr Cynthia McVey, a chartered psychologist who worked as a consultant on Castaway, said the participants on that show – who were chosen to represent a cross-section of society – were far more interested in the lifestyle than being on television.

“The people on Castaway were in the main interested in what it would be like to live like that," she said. "Some of them had already considered changing their lifestyle to live closer to the land, or away from the rat race, or on an island.

“It was also the first Big Brother in Britain and they didn’t have any idea about how reality TV could make you that famous. Nowadays when you go into a reality TV show you get people who want to be famous and people will go to extraordinary lengths.

“In programmes like Big Brother or Towie, people are going on them as they are hopeful of a career in television, whether that is presenting or just becoming a red carpet type celebrity who is in the TV magazines.”

She added: “It is a bit sad when people feel they need a kind of affirmation from fame in order to feel good about themselves. Some of them of course will just do it to make money."

McVey also pointed out reality TV programmes which attempt to push the boundaries and do something different are “difficult and expensive”.

“I think they will become few and far between and what you do get is the ones like Big Brother or Celebrity Big Brother,” she added.

One of the participants in Castaway was Mike Laird, a travel writer and insurance risk manager, who was 30 when he went to live on Taransay a year. He said his motivation for taking part was to experience living a life different from the norm.

“I wanted an experience of self-discovery, to go and face challenges and meet people,” he said. “I was looking for the simple life – for me TV wasn’t a great consideration...I think now there is more the expectation of financial gain, short-term notoriety and possibly for some longer-term fame. I think those are the objectives of some, but not all of the people going into it.”

Laird said his year as a ‘Castaway’ had been a positive experience – although at one point half-way through the year he wanted to leave because he was “bored”.

“It wasn’t because I was having strife with people, it wasn’t because of internal struggles, it was just I thought we have seen the crops grow, we have slaughtered animals and taught children and fished and built this and that,” he said.

“I told the group I don’t really know what we are going to do between now and the end of the year. A year was a massive commitment – that is life-changing.”

As for 'retro-reality', Laird said he believed it was down to “pure voyeurism”.

“The British public have a near insatiable desire to watch individuals and to scrutinise them and comment on them,” he said. “That has very much become a part of the viewing norm now.”