Boris Johnson appointed Mr Lewis to help cut violence among young people
Teachers must take some responsibility for aggressive and anti-social teenagers, London's deputy mayor for young people has said.
Ray Lewis accused schools of being "little villages" only concerned about their own status.
"There is monumental unwillingness to look in the mirror and admit failures," he told a meeting on street violence.
Teachers' unions and the Department for Children, Schools and Families were not immediately available for comment.
Mr Lewis is a former prison governor and ex-director of the Eastside Young Leaders' Academy.
He was appointed by mayor Boris Johnson on Monday to help implement his election pledge to cut violent crime among young people in the capital.
Lack of teachers
Mr Lewis told Thursday's Street Weapons Commission meeting: "Schools are the only businesses which blame their customers for their own failings."
He said the lack of male teachers was a factor behind behavioural problems among boys.
"Schools are failing to provide education fit for males, let alone black males," Mr Lewis said.
"The presence of female teachers who don't look like the boys in their care, let alone boys of colour, is unhelpful. Males have a different psychology to girls."
The meeting will be broadcast as part of a Channel 4 series in June.