Race science was thought to be abandoned after the horrors of World War Two, but award-winning British journalist Angela Saini says not only is it making a comeback, it never really went away.
Her new book, Superior: The Return of Race Science looks at racial biases in the history of science.
She has been described as one of the world's best science writers, regularly presenting science programmes for the BBC and writing for The Guardian and New Scientist.
Her goal is to expose the lie at racism's core: that inequality is a result of genetics rather than political power, that race is a biological characteristic instead of a social construct.
"One of the reasons I wanted to write this book is that I do feel that the scale has tipped back towards the kind of scientific racism we've seen at some of the darkest moments in world history," she tells Kathryn Ryan.
Saini says this can be seen in the rise of ethnic nationalism such as the alt-right, far-right and white supremacy movements. Biology is often invoked as a case for why immigration should be restricted or territories only allowing a certain group of people.
"Many times, racists need biology to make the claims that they're making because if they don't have biology, than what do they have? This is really just a social argument that they're making."
Saini, who's parents are originally from India, said racism was pervasive in London in the 1980s and 1990s. Stephen Lawrence, a black teenager, was murdered by racists near her home. She said it had a profound effect on her and was one of the reasons she became involved in anti-racist movements and got into journalism.
"I grew up in South-East London and this was a strange area. We were one of the few ethnic minorities in the town so it was quite obvious to other people, my race was pointed out to me whether I liked it or not."
She said the British National Party had its headquarters in the same town as her school and she would see Facist marches run through the town.
"On those days, me and my sisters wouldn't be allowed to go out. These were the dominant features of my life. It's very difficult as a child to grow up in that environment and not be affected by it.
"It's always been there in the back of my mind. I've been turning over this topic in my head for so many decades."
Saini said that at the turn of the century it seemed like things had changed and she believed her son wouldn't have to face what she did.
"Now it looks like that's not the case, especially with the Brexit vote, with the election of Trump, with the emboldening of these far-right parties, these white supremacist parties in some cases in Europe.
"It's frightening because you start to feel that perhaps we're going backwards or things are getting worse and the kind of utopian vision I had for the future is not going to happen."
Race as we know it came from European categorisation in the eighteenth century. There were ideas in science that races were different sub-species or breeds of humans.
Saini said Charles Darwin was a product of this categorisation and hierarchy that put white Europeans at the top.
"Science is never completely separate from politics, especially when we're looking at human beings. We have this idea that science is perfectly objective, it sits outside society, it gives us facts that are completely free of any kind of bias. That's never really how science has worked. It's always been rooted in the societies in which it's done. Scientists, of course, are as prone to bias as the rest of us and they have to be very conscious of their biases in order to be able to guard against that and they're not always, especially if the dominant beliefs of a society are a certain way."
Race as a social category is still used in medicine and comes with its own problems. Saini says doctors invoke race when there are statistical chances that a group is more likely to suffer from an ailment. However, she says, these ailments are often symptomatic of cultural differences, for instance, diet, rather than any shared genome in the group.
"In the United States, black Americans tend to die of everything at higher rates than white Americans, including infant mortality leading some doctors to point to race as a factor. However, in the United Kingdom, the gap in life expectancy is dictated much more clearly by the gap in wealth. Saini says the United States is the same."
"It's racialised because poverty and socio-economic status runs along racial lines."
In the late 19th century and early 20th century eugenics, or racial hygiene, was a prominent field of science that argued genetically inferior traits should be removed from society for instance by sterilising criminals or people from a certain race. Adolf Hitler took these ideas to an extreme conclusion with the "final solution" which aimed to eliminate Jews.
"Once upon a time, race science was very mainstream and common all over the world. Eugenics labs were very common in London, in America there was sterilisations of people, and of course, in Germany we know what happened.
"After the Second World War, things changed. Race science, obviously, became unacceptable and there was this kind of global consensus that race had no place in biology. But not all scientists were on board with that consensus. The ones that dissented most loudly, including some Nazi race scientists - people who had carried out experiments on Holocaust victims, the very worst kind of race scientists - clung to these ideas."
She said this group of scientists formed a network and communicated with each other. They started their own fringe journals and would cite each other in articles.
"That network is still around today. It's got bigger, it's changed forms. They've been very smart in the way they've used and abused the science, manipulated arguments, come up with euphemisms to describe human difference to make it look like it's not race science that they're doing, but they are exactly the same people.
One of these scientists is Roger Pearson, who was part of the original network and still part of this group.
"These are the people who kept intellectual racism alive for the last 70 years," Saini says.
"It is now that they're experiencing a resurgence in their ideas. They have managed to spread their tentacles into mainstream politics and mainstream science. The kind of rhetoric that you hear the alt-right and the far-right using comes directly from these people."
Saini also warns that ancestry testing, which spawned out of race science, is very problematic.
"Population genetics was a more respectable, acceptable, and now perfectly mainstream area of research that looks at human variation among population groups. Ancestry testing really emerged out of this. In fact, there are some population geneticists who sit on the board on some of these ancestry testing companies. They use many of the same frameworks. Science, despite its best efforts, has not completely abandoned this idea of race. If it had, it wouldn't be participating in this exercise of grouping people and allowing people to believe that such a thing was possible."
And she says the testing itself is not an exact science.
"All ancestry testing does, is look at your genome and compare it to other people alive today. It's not looking for some racial gene, it can't do that. There is no "white gene" there is no "black gene" there is no "Asian gene". It compares you to other people who've had their genomes tested and looks for commonalities there, in the very margins of the genome, which is why these things are always statistical."