One of the most important breakthroughs in public health came in 1847, when a Hungarian doctor, Ignaz Semmelweis, discovered that surgeons could dramatically cut mortality rates by disinfecting their hands. At the time, he was ridiculed by his medical contemporaries. But today, hand washing remains the cornerstone of lifesaving medical hygiene.

I wonder if we’ve got something important to learn from Semmelweis when it comes to online abuse. Last week, MPs debated a new cross-party report on the rising levels of abuse levelled at election candidates. It found people on all sides of politics being subject to terrible abuse, but particularly women and ethnic minority candidates. While abuse has always been a feature of our politics, there is no doubt it has been turbocharged by the internet and social media.

While it’s hugely positive that this issue is finally getting the parliamentary attention it deserves, the political response has on the whole been utterly depressing. An entirely proper focus on who gets it the worst has morphed into a politicised debate about who is most to blame. Tory MPs have claimed that the Labour party has been too tolerant of online abuse; the chair of the Labour party wrote to the Conservatives ahead of the debate accusing them of perpetrating social media abuse against Labour candidates.

One side might well be worse than the other. But in the words of Diane Abbott, who’s been subjected to some of the most sustained and disgusting sexist and racist abuse in the decades since she entered public life: “The type of abuse I’ve received for years is not the preserve of any party or faction. To say it is devalues a very important argument.” The unedifying spectacle of politicians arguing about who’s most to blame distracts us from asking what can be done to make the situation better.

This is a question of critical importance: not just because it profoundly affects those who choose to serve in politics, but because this sort of abuse is increasingly being faced by women, BAME and LGBTQ people in all walks of public life. And it’s not just adults: with almost four in five children now using social media platforms, the NSPCC has called online bullying “one of the biggest child-protection challenges of this generation”.

It's tempting to fall into the morally superior trap of thinking that the vast majority of us are beyond reproach online

Back to Semmelweis. I wonder if we would do well to apply some of the key lessons from public health to online abuse. Perhaps its most important insight is that when it comes to many problem behaviours that affect our physical and mental wellbeing, we’re not just a collection of individuals whose behaviour is unaffected by others. Instead, in any society, there is a link between behaviour at the average and at the extreme. This means we limit the effectiveness of tackling smoking or obesity by focusing interventions purely on those who are morbidly obese or smoking 40 a day. Instead, we need to view these sorts of behaviours and attitudes on a continuum. It’s why we often see campaigns aimed at shifting the behaviour of everyone, such as the five-a-day campaign, to complement targeted support.

I suspect this insight applies to online abuse. It’s tempting to fall into the morally superior trap of thinking that the vast majority of us are beyond reproach online, with a small group of evil abusers we can’t do anything about. But this prevents us from seeing aggressive, bullying and abusive behaviour lying at one end of the scale. And from recognising that the low-level aggression that’s so easy to practise across social media platforms, which tends to bring out the worst in us by dehumanising the people at the other end, may help facilitate more serious abuse.

This holds us back from thinking how we counter abuse online. Fatalism about abusive behaviour – it’s perpetrated by evil people beyond understanding – breeds acceptance that things can never change. For example, the NSPCC has discovered that people’s fatalistic attitudes to child abuse drive public perceptions that trying to prevent it is futile, despite the evidence to suggest that it can be prevented and that abusers’ behaviour is very much affected by their context.

We shy away from trying to understand things we see as evil because of the fear that this comes dangerously close to justification. But our reluctance to develop understanding actually stops us from preventing bad things from happening. Instead of rushing to say whose lot is worse, we would be much better off seeking to understand what drives the abusers. What’s behind the toxicity they spew? What might get them to stop?

Taking a public health approach to online abuse also involves us accepting that our own behaviour might be important in preventing it: an online equivalent of the broken windows theory of crime. If we all tried to be a bit more civil to each other online, it wouldn’t get rid of abuse altogether, but I bet it would help.

When children are about to message something mean, they get a reminder flash up that it might make their friend feel bad

Social media platforms also need to rethink the way that they approach abuse. At the moment, it’s hard enough to get them even to take decisive action to shut down the most serious abusers. But this whack-a-mole approach should be the absolute minimum we demand. Given the way social media platforms seem to bring out our worst side, they should also be thinking about how to nudge us into being nicer towards each other.

Cybersmarties.com is a social media site designed to foster lifelong positive online behaviour among primary school children in Ireland . When children are about to send a message containing something mean, they get a reminder flashing up that it might make their friend feel bad. That’s clearly too naff an idea for adults, but its central principle of designing a platform to encourage us to be more civil could surely still apply.

While politicians fight among themselves about who’s doing more to encourage it, we’re never going to crack online abuse. Enough of the petty politicisation: we need to invoke Ignaz Semmelweis and take the time to better understand what’s driving the problem and what we can all do about it.