They say don’t speak ill of the dead, and especially not of dead children. But it seems there is an exception to that rule when the subject is black and poor, and meets a violent death. In fact, certain rightwing commentators claim they are are doing us a special favour by suggesting that victims of violent crime, such as 14-year-old Jaden Moodie, are somewhat “gangsta”. Led by figures such as Rod Liddle, who among other things questioned why Jaden was out “at night” (6.30pm actually) and criticised his “fatuous gangsta moves”, these talking heads believe they are courageously owning the identification of a cultural problem: one about which the progressive voices in our society stay silent, for fear of being called racist or politically incorrect.

Of course most violent crime is conducted by white people and the majority of stabbing victims in Britain are white. But as long as any black children are tragically dying on the streets, it is hugely important to debate the causes. The Liddles of this world posit two diagnoses for the problem of black youth violence: absent fathers, and the related claim that the black family is uniquely dysfunctional (and, more nebulously, “black culture”, which is perceived as flawed and nefarious). Yet in direct contrast to the rightwing commentators who exploit this problem to pursue their poisonous agendas, there are people who have been researching and writing about the “ecology” of violence in our cities for decades, making sense of what we are often told is “senseless”. They have found young people living in an “alternative cognitive landscape” in which you stab first and ask questions later; where distrust of the authorities and hostile strangers results in people – and especially young men – arming themselves and acting in aggressive and threatening ways in order to pre-empt attacks.

So how did this state of affairs come to pass? It turns out there are many predictors of violent behaviour more relevant than “absent fathers”: weak social ties, an absence of constructive social activities in which to invest energy, antisocial peers, poor experiences at school, psychological problems, high activity levels and poor eating habits. All these factors relate to poverty, the lack of resources, opportunities, or – frankly – any love from the institutions whose job is to protect, stimulate and engage young people.

This has not stopped the black community self-blaming in a manner that is itself a symptom of the problems in question. The breakdown of the black family is an important line of inquiry, and anyone seriously interested will encounter a powerful and significant history. The group with the highest number of single-parent households in Britain is people of Caribbean heritage, whose ancestors were forcibly prevented from forming strong families by British slavery over generations. This legacy remains a source of pain in the black community, largely unacknowledged by everyone else. In our time, if the state were interested in the wellbeing of black families, I doubt it would be actively trying to deport married black fathers who have been in the country since childhood and are active carers to small children in otherwise stable, two-parent households. Some of these cases have been reported – such as that of Hilary Ineomo-Marcus, who was taken away from his young family and detained for removal last year before being released. It’s unknown how many cases have not.

Many young black people are growing up in a country that they perceive as hostile to their cultural identity and aspirations of progress. Their acts of cultural expression, both here and in all other post-imperial and post-slavery societies, are recognised forms of resistance that have developed in reaction to a mainstream that recognises neither our past nor our future. Incidentally, the universality of these forms of resistance has made black diasporic culture one of the most lucrative capitalist exploits of all time, commoditised through hip-hop, reggae and, yes, drill – which itself has a transatlantic history – as well as black fashion and dance. The black communities that originated these cultural forms are not the ones that have been enriched by their popularity.

I write this not to dismiss, excuse or belittle concerns about the stabbings of black children, but because of how much they trouble me. I am not writing it for Rod Liddle, or others whose track record of crude racism makes it abundantly clear that they have little interest in the tragedies we suffer, but for the dozens of black people I know personally who have started to believe his poisonous narrative too. This problem began with us internalising ideas about our own degeneracy. And it won’t end until we see these ideas for what they are – lies that have endured down the ages.

• Afua Hirsch is a Guardian columnist