Next month sees the release of Trumbo, a biopic about Dalton Trumbo, the screenwriter who was blacklisted by the Hollywood studios after refusing to testify before the House Un-American Activities Committee in 1947. Trumbo continued to work under a variety of pseudonyms and won two Academy Awards for his screenplays, neither of which he was able to receive. He wasn’t rehabilitated until 1960, some 13 years later.

I’ve seen Trumbo and it isn’t much good, but Bryan Cranston has been nominated for numerous awards for his portrayal of the tortured martyr, including a Bafta. People who work in the film industry are, of course, almost universally liberal, and recognising Cranston’s performance is a way of signalling their disapproval of McCarthy-ism. It’s safe to say that, among the progressive left, the House of Un-American Activities has no defenders.

Which makes it all the more ironic that McCarthyism is alive and well and being practiced by the liberal intelligentsia. Last week, I wrote about the punishment meted out to Napoleon Chagnon, the evolutionary anthropologist whose work on the indigenous population of the Amazonian rain forest challenged liberal pieties about the goodness of man in his prelapsarian state. Chagnon was essentially blacklisted by the people who control the anthropology industry. This week I want to highlight another victim of liberal McCarthy-ism — Dr Adam Perkins, a lecturer in the neurobiology of personality at the Institute of Psychiatry, Psychology and Neuroscience at King’s College London. Like Chagnon, Perkins is a social scientist whose research findings pose a direct challenge to one of the central planks of left-wing ideology.

Over the past five years, he has accumulated a mass of evidence about the personalities of welfare claimants and concluded that individuals with aggressive, rule-breaking and anti-social tendencies — what he calls the ‘employment--resistant personality profile’ — are over-represented among benefit recipients. He also found that their children are likely to share those traits, which helps explain why poverty has a tendency to be passed down from one generation to the next.

Now, none of that will surprise anyone who has spent time among the long-term unemployed or their -progeny, such as the police, social workers and teachers. You might even say it’s bleedin’ obvious. But to the progressive left, Perkins’s research is sacrilege. It runs counter to the anti-capitalist narrative that portrays the ever-expanding underclass as ‘victims’ whose only sin is to be born on the wrong side of the tracks. We’re back to the myth of the noble savage.

Perkins published his findings last November in a book called The Welfare Trait (Palgrave Macmillan, £19.99), but you won’t have heard about it or seen it reviewed in any UK newspaper anywhere because his research has been judged to be off limits by the self-appointed guardians of the academic establishment and their outriders in the media. A senior editor of Nature, one of the leading academic journals, refused to consider it for review because she regards scientific research into the personalities of the long-term unemployed as ‘unethical’, and a sociology professor whom the publishers had asked to peer-review the book refused to do so on the grounds that any book linking benefit dependency to personality must be nonsense because personality is a ‘capitalist construct’.

Colleagues with whom Perkins had collaborated in the past warned him off publication, worried about being associated with such a heretic; and a powerful American professor was so enraged by his conclusions that he lobbied for him to be banned from the conference circuit.

‘The basic liberal narrative is that there’s no connection between the individual qualities of unemployed people and their unemployment,’ Adam Perkins explained when I tracked him down on Twitter. ‘They’re just leaves being blown around by the powerful forces of the global economy.’

Perkins says that the link between personality, employability and welfare dependency has been known about for years by academics — ‘It’s old hat, really’ — but until now it’s only been discussed behind closed doors. ‘It’s fear of the political-correctness brigade that has stopped my colleagues going public — quite sensibly, as it turns out,’ he says. ‘But I felt I owed it to the taxpayers who are funding the welfare state to publish these data.’

Let’s hope Adam Perkins doesn’t remain on the blacklist for as long as Dalton Trumbo.

Dr Perkins concluded that individuals with aggressive, rule-breaking and anti-social tendencies are over-represented among benefit recipients

Toby Young is associate editor of The Spectator.