Home Secretary Theresa May was heckled as she said this summer's riots were about money and "instant gratification", not protests about unemployment or cuts.
She told the LSE/Guardian conference on the disturbances that their study was limited and it was important to "draw a more comprehensive and accurate picture of what actually happened this summer".
"The riots weren't about protests, unemployment, cuts," she said. "The riots weren't about the future, about tomorrow.
"They were about today. They were about now. They were about instant gratification. Because all the riots really come down to was money."
Several members of the audience interrupted her 10-minute speech, shouting "No", "Not correct at all", "You shouldn't say things like that" and "Like MPs fiddling expenses". At least one member of the audience walked out.
Mrs May said later: "What the LSE/Guardian report tells me more than anything is that the rioters still have not accepted responsibility for their actions.
"They're still blaming others - the police, the Government, 'society'. They're still making excuses.
"But I don't accept their excuses because it was their choice to riot and their crimes had consequences. So let's not just accept their excuses and their explanations."
Mrs May went on: "Nearly two thirds of those brought before the courts were charged with either burglary, robbery or theft - so we know that the vast mass of rioters weren't protesting, as they claimed; they were thieving.
"Rather than listening solely to the rioters' stories, I think it's important that we take all of the evidence together and that we draw a more comprehensive and accurate picture of what actually happened this summer."
Mrs May did not take any questions after her speech at the conference in central London as she wanted to leave to attend Prime Minister's Questions, the Home Office said.