A pioneering experiment to help people off benefits and into work is being expanded after trials showed that almost 20% of claimants taking part were more likely to get a job three months after signing on than those excluded.

The team of academics that make up Downing Street's Behavioural Insight Team, also known as the nudge unit, used behavioural psychology to achieve the breakthrough. Their techniques included cutting down on the amount of paperwork that claimants had to fill in, as well as building their confidence.

The coalition has faced a barrage of negative publicity over its work programme, which has found sustained work for only 3.5% of claimants – less than the 5% expected if it had done nothing. The nudge unit has been working for the last six months at a jobcentre in Loughton, Essex, where claimants who took part in the trial were around 17.5% more likely than those in a control group to be off benefits, 13 weeks after signing on in the same centre. The changes it has made will be introduced at other jobcentres in the county and in the north-east of England.

The unit made three changes to the way jobseekers in Loughton were treated: the amount of paperwork was reduced at the first meeting so that the claimant could talk about getting back to work from day one; the conversation was focused on what jobseekers would do for the next fortnight and they were encouraged to make written commitments; and advisers at the centre were told to build the confidence and wellbeing of those still claiming after eight weeks, rather than treating them as failures.

The changes affected half of the claimants who attended the centre. Those in the trial had the number of forms they had to sign cut from nine to two. From then on, each time they went to the centre they were encouraged to write down what they hoped to achieve the following week, rather than justifying their previous performance in applying for jobs.

A source said: "We asked them to write these commitments in a way that is supported by the behavioural literature, making the commitments specific, including a 'how', 'what', and a 'when'."

For those still on jobseeker's allowance after eight weeks, the centre created a website where claimants could identify their personality strengths. The website then encouraged them to think of ways to apply those strengths to job applications and everyday life.

The group were also asked to engage on three occasions in expressive writing for 10 to 15 minutes about a traumatic event. A separate randomised trial on a group of engineers found that those who took part in expressive writing were twice as likely to have a job after six months, even though they didn't make more applications than other claimants.

Employment minister Mark Hoban has hailed the Loughton trial, which was carried out with the help of 2,000 unemployed people between June and August. He said: "This government has made important reforms to the welfare state, and this trial shows how taking an innovative approach can help even more people get off benefits."

However, the shadow work and pensions secretary, Liam Byrne, said the government needed to focus on creating jobs, not "tinkering around the edges". He said: "The work programme is worse than doing nothing and our economy isn't growing – this is a national crisis that is not going to be solved by a bit of nudging here and there."

The nudge unit has been criticised as being ineffective in the past, with even policy minister Oliver Letwin admitting it was "open to question whether any of this would have any effect whatsoever".