John's career, spanning social research, education management and youth work, started in 1965, when as a 20-year-old, he left Trinidad for Oxford to study theology as a Dominican friar.
The young monk's transition to social affairs started when he took on the role of education secretary at the Oxford Committee for Racial Integration, which led to his involvement in issues affecting the children of migrant workers in Oxford schools.
"I don't think the schools generally understood the children's background, their language and culture," says John. "And pretty prevalent at the time was the notion that we as Black people are not as intelligent as White people. As a consequence, people were confusing their lack of understanding of the children with lack of intellectual ability."
John's anger at this sparked a current of political activism that has run through his work ever since.
His new career path opened in 1967, when he decided to leave the Dominican order. He felt uneasy with the Roman Catholic Church's stance on apartheid.
John moved to London and worked as a grave digger for 18 months, spending his evenings as a youth worker at a youth club in the crypt of a church in Paddington.
His youth work experience persuaded him to do a diploma in youth and community work in Leicester, cementing his involvement in work with young people, and started a close association with the Youth Service Information Centre, now The National Youth Agency. He spent the next decade immersed in issues affecting Black young people, and in 1973 he was appointed by the National Association of Youth Clubs (now UK Youth), to head research on policies on working with Black young people in 16 towns and cities.
The resulting report highlighted a lack of consistent policies enabling young people of different races to thrive in their environments.
John doesn't believe much has changed since then. He views the Government's drive towards community cohesion as "farcical": "Places like Southall and Slough didn't just become like that. Estate agents said that to live around Black people lowered the value of your home, so White people moved out.
"We have to understand that the Government's concern about community cohesion is the concern that should have been there when White people were moving in droves from their homes."
John attributes the widely reported underachievement of Black young men to failures in both governments over the past two decades; the undermining of the social education agenda at the hands of the Conservatives and, ironically, the "education, education, education" agenda pushed by Tony Blair.
"With Labour, the focus on raising achievement tended to displace the time that teachers used to spend trying to help young people's self-development and behaviour management," he says. John agrees with the Every Child Matters agenda "to a point", but is concerned about its conflict with the zero-tolerance approach to bad behaviour, which the Government also encourages.
Since 1996, when he left his role in Hackney as the first Black chief education officer in the country, John has put his energy into consultancy work.
"The system has failed so many Black young men, they don't see the point in putting themselves through it," he says. "I don't think the picture is rosy. It seems the youth service will be reconstructed, and will be expected to pick up casualties from the school system."
- Gus John, 61, heads the Gus John Partnership, an international consultancy formed in 2000 to promote equality, diversity and urban regeneration
- He is also a visiting professor of education at the University of Strathclyde
- His most recent publication is Taking a Stand, a book of his writing tackling issues of education, race, social action and civil unrest between 1980 and 2005, which follows on from his book In the Service of Black Youth published in 1981.