News on Relevant Science: March 2018

Tuesday, March 20, 2018

David Reich Unearths Human History Etched in Bone

The geneticist at Harvard Medical School has retrieved
DNA from more than 900 ancient people. His
findings trace the prehistoric migrations of our species.

By CARL ZIMMER MARCH 20, 2018

BOSTON — David Reich wore a hooded, white suit, cream-colored clogs, and a blue surgical mask. Only his eyes were visible as he inspected the bone fragments on the counter.

Dr. Reich, a geneticist at Harvard Medical School, pointed out a strawberry-sized chunk: “This is from a 4,000-year-old site in Central Asia — from Uzbekistan, I think.”

He moved down the row. “This is a 2,500-year-old sample from a site in Britain. This is Bronze Age Russian, and these are Arabian samples. These people would have never met each other in time or space.”

Dr. Reich hopes that his team of scientists and technicians can find DNA in these bones. Odds are good that they will.

David Reich in his office at Harvard. He and his colleagues have sequenced the genomes of more than 900 ancient individuals, shedding light on how humans spread across the globe. Credit Kayana Szymczak for The New York Times

In less than three years, Dr. Reich’s laboratory has published DNA from the genomes of 938 ancient humans — more than all other research teams working in this field combined. The work in his lab has reshaped our understanding of human prehistory.

“They often answer age-old questions and sometimes provide astonishing unanticipated insights,” said Svante Paabo, the director of the Max Planck Institute of Paleoanthropology in Leipzig, Germany.

Dr. Reich, Dr. Paabo and other experts in ancient DNA are putting together a new history of humanity, one that runs in parallel with the narratives gleaned from fossils and written records. In Dr. Reich’s research, he and his colleagues have shed light on the peopling of the planet and the spread of agriculture, among other momentous events.

In a book to be published next week, “Who We Are and How We Got Here,” Dr. Reich, 43, explains how advances in DNA sequencing and analysis have helped this new field take off.

“It’s really like the invention of a new scientific instrument, like a microscope or a telescope,” he said. “When an instrument that powerful is invented, it opens up all these horizons, and everything is new and surprising.”

Dr. Reich oversees a team with many different skills, from genetics to mathematics. But the “clean lab” is where the raw material for all their work — ancient DNA — is recovered. The head-to-toe suits that the researchers don in an airlock each morning ensure that no stray flake of skin or bead of sweat contaminates the bones with modern DNA. Each night the entire lab is bathed in gene-destroying ultraviolet light.

Interpreting Ancient DNA

A new book by David Reich, a geneticist at Harvard Medical School, details his laboratory’s findings on prehistoric human migrations and the complex mixing of different populations. This map shows some of those migrations, including the expansion of modern humans from Africa and the Near East, and several major mixing events.

The clean lab feels like it belongs in a computer chip factory. But Dr. Reich has not forgotten that these are human remains, not widgets on a conveyor belt.

“This is a bone from a person’s body who lived four thousand years ago, and we’re destroying it,” he said, gazing down at the Uzbek remains. “I think we need to do well by the individuals we’re studying.”

Doing well means understanding who these people were, and how they were linked to one another — and to us.

Standing next to Dr. Reich was a suited technician, Ann Marie Lawson. She picked up the Uzbek bone and lowered it into a box, which she covered with a clear plastic lid. She pushed her gloved hands through two rubber-lined holes on its sides.

She picked up the bone in her left hand; with her right hand, she switched on a sandblasting hose and pointed it at the bone. An outer layer of dirt flew upward, quickly sucked away by a fan in the box.

Mr. Oppenheimer at work in Dr. Reich’s lab. DNA recovered from a small piece of bone can tell scientists about human migrations over thousands of years. Credit Kayana Szymczak for The New York Times

Ms. Lawson then inspected the freshly white bone. It came from the base of a skull, and deep inside was the inner ear. The bone that surrounds the inner ear turns out to be the best place in the body to search for ancient DNA.

Ms. Lawson began sandblasting again, chiseling away chunks of bone. Eventually, she was left holding a remnant only as big as a grain of rice.

“That’s the motherlode,” said Dr. Reich.

An Extraordinary Invitation

Dr. Reich grew up in Washington, the son of the novelist Tova Reich and Walter Reich, the first director of the Holocaust Memorial Museum and now a professor at George Washington University.

Dr. Reich began studying sociology as a Harvard undergraduate, but later he turned to physics and then to medicine. After graduating, he went to Oxford to prepare for medical school.

There he met Dr. David B. Goldstein, who at the time was comparing the DNA of living people for clues to what their distant ancestors were like.

“When I first met him, he was obviously smart, but he gave an impression of being a little bit shy and not having a very forceful personality,” said Dr. Goldstein.

“It turned out that’s the most misleading impression he could possibly give. He knows exactly what he wants to do.”

It was obvious that his student was captivated by the research. But Dr. Goldstein had come to view it as a scientific dead end.

“I said, ‘My God, don’t spend your career on human evolutionary genetics,” recalled Dr. Goldstein, who now studies disease genetics at Columbia University.

“He just listened very politely and wasn’t persuaded an iota,” he added with a laugh. “He wasn’t just proven right. He was proved dramatically right.”

The cochlea, or inner ear, extracted by Mr. Oppenheimer. It may contain DNA that is tens of thousands of years old. Credit Kayana Szymczak for The New York Times

Abandoning medical school, Dr. Reich continued with genetics research and was hired by Harvard Medical School in 2003. By then, he had developed a close partnership with a mathematician named Nick Patterson, who had come late in life to genetics after twenty years working as a cryptographer in British intelligence and then joining a hedge fund.

Dr. Reich appointed Dr. Patterson deputy head of the newly formed genetics lab, and together they began developing new statistical techniques to plumb genetic data for hidden patterns.

The two researchers devised a way to determine whether a single population descended from two or more distinct groups. Collaborating with researchers at the Center for Cellular and Molecular Biology in Hyderabad, India, they put their method to its first big test.

Analyzing DNA from hundreds of villages, they discovered that just about every living Indian descends from two distinct groups. One, which the researchers called Ancestral North Indians, is related to Central Asians, Near Easterners and Europeans.

The second group, Ancestral South Indians, is a mysterious population that is not closely related to any living people outside of India. The two populations mixed together, Dr. Reich estimated, 2,000 to 4,000 years ago.

As Dr. Reich and his colleagues gained attention for their new methods, they got an extraordinary invitation: to study the DNA of Neanderthals.

A Mysterious Lineage

The invitation came from Dr. Paabo. In the 1990s, he had pioneered methods to extract ancient DNA from fossils dating back tens of thousands of years. While he studied many extinct species — such as cave bears, mastodons and ground sloths — Neanderthals were his deepest passion.

Fossils of these heavy-browed individuals date back over 200,000 years in Europe and the Near East. They made tools, weapons and even cave art. But they vanished about 40,000 years ago.

Dr. Paabo gradually filled in gaps to reconstruct the entire Neanderthal genome. In 2006, he invited Dr. Reich’s team to help figure out how modern humans and Neanderthals were related.

Dr. Reich threw himself into the project, and over the next few years, the scientists made a series of landmark discoveries.

The DNA of Neanderthals indicates that their ancestors split from our own about 600,000 years ago. But Dr. Reich’s tests revealed that living humans outside of Africa still carry traces of Neanderthal DNA.

How is that possible? Before Neanderthals became extinct in Europe, they encountered and interbred with the ancestors of modern humans as they departed Africa.

Mr. Oppenheimer works with a machine handling bones samples. Credit Kayana Szymczak for The New York Times

As the scientists searched in more fossils for Neanderthal DNA, they got another surprise. In 2010, a nondescript pinkie bone recovered in a Siberian cave called Denisova yielded the entire genome of a previously unknown, and extinct, lineage of humans.

The Denisovans, as they came to be known, split off from Neanderthals about 400,000 years ago, genetic analysis revealed.

Denisovan DNA has turned up only in a few additional teeth discovered in that Siberian cave. The oldest such fossils date to over 100,000 years old; the pinkie bone belonged to a Denisovan who lived sometime between 48,000 and 60,000 years ago.

Dr. Reich and his colleagues discovered that Denisovans, like Neanderthals, left a genetic legacy in living people, mostly in Australia, New Guinea and Asia.

Their research also suggested that Denisovans divided early in their history into two lineages. “They were isolated from each other for many hundreds of thousands of years,” said Dr. Reich.

A study published on Thursday by Princeton geneticist Joshua Akey and his colleagues confirmed this finding and brought D enisovans into sharper focus.

Each branch, the new study suggests, interbred with the ancestors of living humans. One Denisovan group left behind DNA in modern-day Asians and Oceanians. The other branch left genetic traces only in living people in China and Japan.

A cochlea, left, is measured in Dr. Reich’s lab. Right, a lab technician prepares to extract DNA. Credit Kayana Szymczak for The New York Times

Ancient DNA has summoned the genetic shadows of a long-vanished people, one that fossils alone could not reveal. Many scientists now suspect that ancient DNA will reveal other extinct kinds of humans in the future.

“The discovery of Denisovan DNA was a landmark in my thinking about ancient DNA,” said Dr. Reich. “It can reveal things about the past that are completely unexpected, that are not dreamed of in our philosophy.”

Setting the ‘Traps’

Dr. Reich’s voyage through prehistory left him wondering about what DNA could reveal about more recent events. Museums around the world were loaded with bones of people who lived within the last 20,000 years, after all.

Since those remains were younger, they’d be more likely to still have some DNA in them. To begin retrieving it, Dr. Reich retooled his laboratory, copying Dr. Paabo’s facility in Germany to the last detail.

“We even cloned the linoleum from Leipzig,” he said.

But in important ways, Dr. Reich broke from the standard scientific strategy for searching for ancient DNA.

Dr. Paabo and other experts typically examine many fossils to find a rare one packed with DNA. They then try to reconstruct the entire genome.

Dr. Reich’s lab instead designed DNA “traps” that snag hundreds of thousands of genetic fragments from the human genome. The result is far from a complete genome sequence, but enough to divine ancestries and even get some clues about the traits of ancient people.

In 2015, the first results emerged from Dr. Reich’s new research pipeline. He and his colleagues published DNA from 69 ancient Europeans who lived 3,000 to 8,000 years ago.

According to their results, farmers with Near East ancestry displaced hunter-gatherers already living in Europe. Then, about 4,500 years ago, another wave of people arrived, descended from the horse-riding nomads of what are now the Russian steppes.

Less than three years since that study, Dr. Reich’s team has published a torrent of similar findings. They have traced the spread of the first farmers in the Near East, for example, and have tracked the rise and fall of various populations in ancient Africa.

While some of these results describe migrations across continents, Dr. Reich’s team also focuses on smaller regions to reconstruct the genetic makeup of people over thousands of years.

Recently, for example, Dr. Reich and his colleagues published the DNA of people who lived on what are now the British Isles 3,500 to 10,000 years ago. It, too, tells a story.

When the Ice Age glaciers retreated from the islands, hunter-gatherers moved in from what is now Europe. About 6,000 years ago, farmers with Near Eastern ancestry reached Britain, and mostly replaced the hunter-gatherers.

About 4,500 years ago, archaeologist have found, there was a sudden shift in Britain to new styles of pottery and metalworking, known collectively as the Beaker culture. Many experts have argued that farmers borrowed the techniques from the European continent.

But the DNA says otherwise, Dr. Reich and his colleagues found. While the Beaker culture spread from society to society on the mainland, it was brought to Britain by immigrants descended from the nomads of what are now the R ussian steppes.

A tray in Dr. Reich’s lab holding ancient bones to be examined for DNA. Credit Kayana Szymczak for The New York Times

These people almost entirely replaced the earlier farmers. Today, British people trace 90 percent of their ancestry to this immigrant wave.

Were it not for the genetic findings, “nobody would have believed the scale of the turnover,” said Ian Armit, an archaeologist at the University of Bradford who collaborated with Dr. Reich on the research.

“Archaeologists will need to get to grips with this 90 percent replacement, and what this might really mean in human terms,” he added.

A Dramatic Voyage

The Beaker people needed only to cross the English Channel to get to the British Isles. A far more spectacular voyage took place about 3,300 years ago, when humans first sailed to remote islands in the Pacific.

Dr. Reich and his colleagues have shed light on that migration by analyzing ancient DNA from the skeletons of early Pacific voyagers.

“It’s changed the game,” said Matthew Spriggs, an archaeologist at Australian National University, who has collaborated with Dr. Reich.

Until recently, many archaeologists argued that the ancestors of Pacific Islanders were related to the indigenous people of Taiwan. They had sailed south to the islands around New Guinea, the idea went, later mixing with the population, known as Papuans. Only later did their descendants sail east to Pacific islands.

This theory helped account for the kinds of languages spoken in the Pacific, the agriculture, and styles of pottery, as well as the mix of East Asian and New Guinea DNA found in the islanders.

Dr. Spriggs and other archaeologists provided Dr. Reich with bones from Vanuatu and Tonga, and his team succeeded in recovering DNA where others had failed. And what did it say about the prevailing theory?

“We found genetically that wasn’t right at all,” Dr. Reich said. He and his colleagues published their results last month in the journal Current Biology.

Instead, the people who first arrived on Vanuatu and other Pacific islands came directly from Asia — perhaps Taiwan or the Philippines — without ever stopping in New Guinea. Only later did a wave of Papuans arrive.

“We know now when that wave hits — it hits before 2,400 years ago,” said Dr. Reich. “And it’s a total replacement.”

And that second wave actually was made up of at least two migrations. The Papuans who came to what is now Vanuatu probably sailed from the Bismarck Islands. But the Papuans who arrived further east, in Polynesia, came from other islands, possibly New Britain.

As of last month, Dr. Reich’s team has published about three-quarters of all the genome-wide data from ancient human remains in the scientific literature. But the scientists are only getting started.

They also have retrieved DNA from about 3,000 more samples. And the lab refrigerators are filled with bones from 2,000 more denizens of prehistory.

Dr. Reich’s plan is to find ancient DNA from every culture known to archaeology everywhere in the world. Ultimately, he hopes to build a genetic atlas of humanity over the past 50,000 years.

“I try not to think about it all at once, because it’s so overwhelming,” he said.

Correction: March 20, 2018
An earlier version of this article misstated the given name of a mathematician. He is Nick Patterson, not Neil.

Jonas Oppenheimer, a technician in the lab of David Reich, a geneticist at Harvard, sandblasts an ancient skull fragment to find the cochlea, or inner ear, the area likeliest to retain DNA. Kayana Szymczak for The New York Times

NYT

Saturday, March 17, 2018

How Trump Consultants Exploited the Facebook Data of Millions

By MATTHEW ROSENBERG, NICHOLAS CONFESSORE and CAROLE CADWALLADR MARCH 17, 2018

Christopher Wylie, who helped found the data firm Cambridge Analytica and worked there until 2014, has described the company as an “arsenal of weapons” in a culture war. Credit Andrew Testa for The New York Times

LONDON — As the upstart voter-profiling company Cambridge Analytica prepared to wade into the 2014 American midterm elections, it had a problem.

The firm had secured a $15 million investment from Robert Mercer, the wealthy Republican donor, and wooed his political adviser, Stephen K. Bannon, with the promise of tools that could identify the personalities of American voters and influence their behavior. But it did not have the data to make its new products work.

So the firm harvested private information from the Facebook profiles of more than 50 million users without their permission, according to former Cambridge employees, associates and documents, making it one of the largest data leaks in the social network’s history. The breach allowed the company to exploit the private social media activity of a huge swath of the American electorate, developing techniques that underpinned its work on President Trump’s campaign in 2016.

An examination by The New York Times and The Observer of London reveals how Cambridge Analytica’s drive to bring to market a potentially powerful new weapon put the firm — and wealthy conservative investors seeking to reshape politics — under scrutiny from investigators and lawmakers on both sides of the Atlantic.

Both Congress and the British Parliament have questioned Alexander Nix, chief executive of Cambridge Analytica, about the firm’s activities. Credit Bryan Bedder/Getty Images

Christopher Wylie, who helped found Cambridge and worked there until late 2014, said of its leaders: “Rules don’t matter for them. For them, this is a war, and it’s all fair.”

“They want to fight a culture war in America,” he added. “Cambridge Analytica was supposed to be the arsenal of weapons to fight that culture war.”

Details of Cambridge’s acquisition and use of Facebook data have surfaced in several accounts since the business began working on the 2016 campaign, setting off a furious debate about the merits of the firm’s so-called psychographic modeling techniques.

But the full scale of the data leak involving Americans has not been previously disclosed — and Facebook, until now, has not acknowledged it. Interviews with a half-dozen former employees and contractors, and a review of the firm’s emails and documents, have revealed that Cambridge not only relied on the private Facebook data but still possesses most or all of the trove.

Cambridge paid to acquire the personal information through an outside researcher who, Facebook says, claimed to be collecting it for academic purposes.

During a week of inquiries from The Times, Facebook downplayed the scope of the leak and questioned whether any of the data still remained out of its control. But on Friday, the company posted a statement expressing alarm and promising to take action.

“This was a scam — and a fraud,” Paul Grewal, a vice president and deputy general counsel at the social network, said in a statement to The Times earlier on Friday. He added that the company was suspending Cambridge Analytica, Mr. Wylie and the researcher, Aleksandr Kogan, a Russian-American academic, from Facebook. “We will take whatever steps are required to see that the data in question is deleted once and for all — and take action against all offending parties,” Mr. Grewal said.

Alexander Nix, the chief executive of Cambridge Analytica, and other officials had repeatedly denied obtaining or using Facebook data, most recently during a parliamentary hearing last month. But in a statement to The Times, the company acknowledged that it had acquired the data, though it blamed Mr. Kogan for violating Facebook’s rules and said it had deleted the information as soon as it learned of the problem two years ago.

In Britain, Cambridge Analytica is facing intertwined investigations by Parliament and government regulators, who are scrutinizing possible data privacy violations and allegations that it performed illegal work on the “Brexit” campaign. In the United States, Mr. Mercer’s daughter, Rebekah, a board member, Mr. Bannon and Mr. Nix received warnings from their lawyer that it was illegal to employ foreigners in political campaigns, according to company documents and former employees.

The conservative donor Robert Mercer invested $15 million in Cambridge Analytica, where his daughter Rebekah is a board member. Credit Patrick McMullan, via Getty Images

Congressional investigators have questioned Mr. Nix about the company’s role in the Trump campaign. And the Justice Department’s special counsel, Robert S. Mueller III, has demanded the emails of Cambridge Analytica employees who worked for the Trump team as part of his investigation into Russian interference in the election.

While the substance of Mr. Mueller’s interest is a closely guarded secret, documents viewed by The Times indicate that the firm’s British affiliate claims to have worked in Russia and Ukraine. And the WikiLeaks founder, Julian Assange, disclosed in October that Mr. Nix had reached out to him during the campaign in hopes of obtaining private emails belonging to Mr. Trump’s Democratic opponent, Hillary Clinton.

The documents also raise new questions about Facebook, which is already grappling with intense criticism over the spread of Russian propaganda and fake news. The data Cambridge collected from profiles, a portion of which was viewed by The Times, included details on users’ identities, friend networks and “likes.”

“Protecting people’s information is at the heart of everything we do,” Mr. Grewal said. “No systems were infiltrated, and no passwords or sensitive pieces of information were stolen or hacked.”

Still, he added, “it’s a serious abuse of our rules.”

Reading Voters’ Minds

The Bordeaux flowed freely as Mr. Nix and several colleagues sat down for dinner at the Palace Hotel in Manhattan in late 2013, Mr. Wylie recalled in an interview. They had much to celebrate.

Mr. Nix, a brash salesman, led the small elections division at SCL Group, a political and defense contractor. He had spent much of the year trying to break into the lucrative new world of political data, recruiting Mr. Wylie, then a 24-year-old political operative with ties to veterans of President Obama’s campaigns. Mr. Wylie was interested in using inherent psychological traits to affect voters’ behavior and had assembled a team of psychologists and data scientists, some of them affiliated with Cambridge University.

The group experimented abroad, including in the Caribbean and Africa, where privacy rules were lax or nonexistent and politicians employing SCL were happy to provide government-held data, former employees said.

Then a chance meeting bought Mr. Nix into contact with Mr. Bannon, the Breitbart News firebrand who would later become a Trump campaign and White House adviser, and with Mr. Mercer, one of the richest men on earth.

Mr. Nix and his colleagues courted Mr. Mercer, who believed a sophisticated data company could make him a kingmaker in Republican politics, and his daughter Rebekah, who shared his conservative views. Mr. Bannon was intrigued by the possibility of using personality profiling to shift America’s culture and rewire its politics, recalled Mr. Wylie and other former employees, who spoke on the condition of anonymity because they had signed nondisclosure agreements. Through a spokeswoman, Mr. Bannon declined to comment.

Mr. Mercer agreed to help finance a $1.5 million pilot project to poll voters and test psychographic messaging in Virginia’s gubernatorial race in November 2013, where the Republican attorney general, Ken Cuccinelli, ran against Terry McAuliffe, the Democratic fund-raiser. Though Mr. Cuccinelli lost, Mr. Mercer committed to moving forward.

The Mercers wanted results quickly, and more business beckoned. In early 2014, the investor Toby Neugebauer and other wealthy conservatives were preparing to put tens of millions of dollars behind a presidential campaign for Senator Ted Cruz of Texas, work that Mr. Nix was eager to win.

When Mr. Wylie’s colleagues failed to produce a memo explaining their work to Mr. Neugebauer, Mr. Nix castigated them over email.

“ITS 2 PAGES!! 4 hours work max (or an hour each). What have you all been doing??” he wrote.

Mr. Wylie’s team had a bigger problem. Building psychographic profiles on a national scale required data the company could not gather without huge expense. Traditional analytics firms used voting records and consumer purchase histories to try to predict political beliefs and voting behavior.

But those kinds of records were useless for figuring out whether a particular voter was, say, a neurotic introvert, a religious extrovert, a fair-minded liberal or a fan of the occult. Those were among the psychological traits the firm claimed would provide a uniquely powerful means of designing political messages.

Aleksandr Kogan, a Russian-American academic, built an app that helped the firm harvest Facebook data.

Mr. Wylie found a solution at Cambridge University’s Psychometrics Centre. Researchers there had developed a technique to map personality traits based on what people had liked on Facebook. The researchers paid users small sums to take a personality quiz and download an app, which would scrape some private information from the their profiles and those of their friends, activity that Facebook permitted at the time. The approach, the scientists said, could reveal more about a person than their parents or romantic partners knew — a claim that has been disputed.

When the Psychometrics Centre declined to work with the firm, Mr. Wylie found someone who would: Dr. Kogan, who was then a psychology professor at the university and knew of the techniques. Dr. Kogan built his own app and in June 2014 began harvesting data for Cambridge Analytica. The business covered the costs — more than $800,000 — and allowed him to keep a copy for his own research, according to company emails and financial records.

All he divulged to Facebook, and to users in fine print, was that he was collecting information for academic purposes, the social network said. It did not verify his claim. Dr. Kogan declined to provide details of what happened, citing nondisclosure agreements with Facebook and Cambridge Analytica, though he maintained that his program was “a very standard vanilla Facebook app.”

He ultimately provided over 50 million raw profiles to the firm, Mr. Wylie said, a number confirmed by a company email and a former colleague. Of those, roughly 30 million contained enough information, including places of residence, that the company could match users to other records and build psychographic profiles. Only about 270,000 users — those who participated in the survey — had consented to having their data harvested.

An email from Dr. Kogan to Mr. Wylie describing traits that could be predicted.

Mr. Wylie said the Facebook data was “the saving grace” that let his team deliver the models it had promised the Mercers.

“We wanted as much as we could get,” he acknowledged. “Where it came from, who said we could have it — we weren’t really asking.”

Mr. Nix tells a different story. Appearing before a parliamentary committee last month, he described Dr. Kogan’s contributions as “fruitless.”

An International Effort

Just as Dr. Kogan’s efforts were getting underway, Mr. Mercer agreed to invest $15 million in a joint venture with SCL’s elections division. The partners devised a convoluted corporate structure, forming a new American company, owned almost entirely by Mr. Mercer, with a license to the psychographics platform developed by Mr. Wylie’s team, according to company documents. Mr. Bannon, who became a board member and investor, chose the name: Cambridge Analytica.

The firm was effectively a shell. According to the documents and former employees, any contracts won by Cambridge, originally incorporated in Delaware, would be serviced by London-based SCL and overseen by Mr. Nix, a British citizen who held dual appointments at Cambridge Analytica and SCL. Most SCL employees and contractors were Canadian, like Mr. Wylie, or European.

But in July 2014, an American election lawyer advising the company, Laurence Levy, warned that the arrangement could violate laws limiting the involvement of foreign nationals in American elections.

In a memo to Mr. Bannon, Ms. Mercer and Mr. Nix, the lawyer, then at the firm Bracewell & Giuliani, warned that Mr. Nix would have to recuse himself “from substantive management” of any clients involved in United States elections. The data firm would also have to find American citizens or green card holders, Mr. Levy wrote, “to manage the work and decision making functions, relative to campaign messaging and expenditures.”

In summer and fall 2014, Cambridge Analytica dived into the American midterm elections, mobilizing SCL contractors and employees around the country. Few Americans were involved in the work, which included polling, focus groups and message development for the John Bolton Super PAC, conservative groups in Colorado and the campaign of Senator Thom Tillis, the North Carolina Republican.

Cambridge Analytica, in its statement to The Times, said that all “personnel in strategic roles were U.S. nationals or green card holders.” Mr. Nix “never had any strategic or operational role” in an American election campaign, the company said.

Whether the company’s American ventures violated election laws would depend on foreign employees’ roles in each campaign, and on whether their work counted as strategic advice under Federal Election Commission rules.

Cambridge Analytica appears to have exhibited a similar pattern in the 2016 election cycle, when the company worked for the campaigns of Mr. Cruz and then Mr. Trump. While Cambridge hired more Americans to work on the races that year, most of its data scientists were citizens of the United Kingdom or other European countries, according to two former employees.

Under the guidance of Brad Parscale, Mr. Trump’s digital director in 2016 and now the campaign manager for his 2020 re-election effort, Cambridge performed a variety of services, former campaign officials said. That included designing target audiences for digital ads and fund-raising appeals, modeling voter turnout, buying $5 million in television ads and determining where Mr. Trump should travel to best drum up support.

Cambridge executives have offered conflicting accounts about the use of psychographic data on the campaign. Mr. Nix has said that the firm’s profiles helped shape Mr. Trump’s strategy — statements disputed by other campaign officials — but also that Cambridge did not have enough time to comprehensively model Trump voters.

In a BBC interview last December, Mr. Nix said that the Trump efforts drew on “legacy psychographics” built for the Cruz campaign.

After the Leak

By early 2015, Mr. Wylie and more than half his original team of about a dozen people had left the company. Most were liberal-leaning, and had grown disenchanted with working on behalf of the hard-right candidates the Mercer family favored.

Cambridge Analytica, in its statement, said that Mr. Wylie had left to start a rival firm, and that it later took legal action against him to enforce intellectual property claims. It characterized Mr. Wylie and other former “contractors” as engaging in “what is clearly a malicious attempt to hurt the company.”

Near the end of that year, a report in The Guardian revealed that Cambridge Analytica was using private Facebook data on the Cruz campaign, sending Facebook scrambling. In a statement at the time, Facebook promised that it was “carefully investigating this situation” and would require any company misusing its data to destroy it.

Facebook verified the leak and — without publicly acknowledging it — sought to secure the information, efforts that continued as recently as August 2016. That month, lawyers for the social network reached out to Cambridge Analytica contractors. “This data was obtained and used without permission,” said a letter that was obtained by the Times. “It cannot be used legitimately in the future and must be deleted immediately.”

Mr. Grewal, the Facebook deputy general counsel, said in a statement that both Dr. Kogan and “SCL Group and Cambridge Analytica certified to us that they destroyed the data in question.”

Cambridge Analytica harvested over 50 million Facebook users’ data, one of the largest data leaks in the social network’s history. Credit Justin Sullivan/Getty Images

But copies of the data still remain beyond Facebook’s control. The Times viewed a set of raw data from the profiles Cambridge Analytica obtained.

While Mr. Nix has told lawmakers that the company does not have Facebook data, a former employee said that he had recently seen hundreds of gigabytes on Cambridge servers, and that the files were not encrypted.

Today, as Cambridge Analytica seeks to expand its business in the United States and overseas, Mr. Nix has mentioned some questionable practices. This January, in undercover footage filmed by Channel 4 News in Britain and viewed by The Times, he boasted of employing front companies and former spies on behalf of political clients around the world, and even suggested ways to entrap politicians in compromising situations.

All the scrutiny appears to have damaged Cambridge Analytica’s political business. No American campaigns or “super PACs” have yet reported paying the company for work in the 2018 midterms, and it is unclear whether Cambridge will be asked to join Mr. Trump’s re-election campaign.

In the meantime, Mr. Nix is seeking to take psychographics to the commercial advertising market. He has repositioned himself as a guru for the digital ad age — a “Math Man,” he put s it. In the United States last year, a former employee said, Cambridge pitched Mercedes-Benz, MetLife and the brewer AB InBev, but has not signed them on.

Matthew Rosenberg, Nicholas Confessore and Carole Cadwalladr reported from London. Gabriel J.X. Dance contributed reporting from London, and Danny Hakim from New York.

NYT

News on Relevant Science

Tuesday, March 20, 2018

David Reich Unearths Human History Etched in Bone