There may be evidence to suggest that children as young as three years old may already be "classifying" people.

According to Lord Herman Ouseley, the former chairman of the Commission for Racial Equality, children need to "play together right from day one," to avoid becoming racists.

Lord Ouseley believes, teachers should "discourage separate play" and "help children to unlearn any racist attitudes and behavior they may have already learn."

"It is important to consider whether patterns of play are consistently based on racial or cultural grounds."

According to Lord Ouseley, "If, for example, Muslim children nearly always play together and seldom play with other children, the question needs to be asked, 'Is there a reason for it that may relate to culture? Or apprehension? Or prejudice?'"

The advice comes in the latest issue of the journal, Race Equality Teaching, where Jane Lane, a co-author of the article and an early-years equality adviser adds that the conventional wisdom that toddlers were "color blind" was wrong.

Jane says, "There is a view that children do not learn their attitudes until they are about five.

"But people in the early years know that children at a very early age - at the age of three - are categorizing people. I am not talking about white children; I am talking about all children. Many, many are racially prejudiced, for all sorts of historical reasons."