Harriett Wilson, who has died aged 85, is best known as the founder of the Child Poverty Action Group. Just as important was her contribution to the study of deprived children.

Born as Harriett Friedeberg in Germany in 1916, she married a Jew, Harrow Veit Simon, and was forced to flee from the Nazis in 1935. The couple moved to Britain where they had a child, John, but they divorced in 1938. Soon Harriett found herself a lone parent in a country at war with her own nation. Somehow they survived on her low income as a shop worker in Cambridge.

In her mid-thirties, she completed a degree in sociology at the London School of Economics. In 1946, she married Arthur Wilson, a Canadian crystallographer, and they moved to Cardiff where Harriett did a PhD at the University of Wales.

Harriett joined with other Quakers in Cardiff to set up an innovative play centre for children from poor backgrounds.

She then published a book which identified the association between delinquency and poverty. The book, Delinquency and Child Neglect (Allen & Unwin, 1962), established her reputation and two years later she wrote a pamphlet for the Quakers which argued that the welfare state had not abolished poverty.

A socialist, she had hoped that the Labour government of 1964 would increase substantially the levels of family allowances, as child benefit was then called. When this did not happen, she headed a group of Quakers who called a meeting at Toynbee Hall in 1965. It led to the founding of the Child Poverty Action Group with Harriett as its vice chair until 1981. Today the Child Poverty Action Group is Britain's foremost anti-poverty agency.

Harriett and Arthur moved to the University of Birmingham where Arthur had a professorial chair. It was here, in the 1960s, that I got to know her as a fellow member of a United Nations working group on socially deprived families. Given to hospitality, Harriett often entertained my wife, Annette, myself and our children.

As expected, she displayed a capacity to communicate with young children. Not so expected, was a sense of fun which was not so evident in her public lectures.

As senior research fellow at the centre for child study at the University of Birmingham, she undertook her most significant research with the psychologist, Geoffrey Herbert. They compared the child-rearing methods of poor parents and the development of their children with affluent families. The interviews were carried out by Annette Holman who visited the families periodically. The results, published in 1978 as Children and Parents in the Inner City (Routledge & Kegan Paul), showed that children were socially handicapped when raised by parents who did not encourage their learning, supervise them closely, and provide leisure facilities.

However, it also revealed that the child-care values and aspirations of poor parents were similar to those of affluent parents but they lacked the money and resources to implement best practice.

The book remains a classic study of the connection between poverty and child-rearing.

Although gentle in disposition, she publicly challenged Sir Keith Joseph, the Conservative minister for social services, when in 1972 he broadcast his cycle of deprivation thesis which claimed that inadequate parents bred inadequate children and that the solutions were playgroups to improve the children's behaviour and parenting classes to improve the parents. Harriett insisted that any programmes had to be in conjunction with policies to take the families out of poverty.

In her last years, Harriett Wilson suffered Alzheimer's. Her first son, John, is a professor of social policy and a poverty campaigner. Her happy marriage to Arthur ended with his death

in 1995.

Their son, Howard, a research chemist, died in 2001. Their daughter, Mary Fullbrook, is a professor of German history at London University. She also leaves eight grandchildren.

Harriett Charlotte Wilson, child poverty campaigner; born September 14, 1916, died July 14, 2002.