In the wake of a murder at a shelter for young refugees, Sweden's government has come under pressure to carry out age checks on those who claim to be under 18. Swedish law protects unaccompanied minors from deportation.
"Just how old do you think these migrant 'children' are?" the headline in Britain's right-wing Daily Mail newspaper screamed at the end of last month, above a picture (photo below) of a young man, dubbed "the fastest 14-year-old in Sweden," jogging among a group of much younger looking children. "He looks old enough to be the father of the children he is jogging with," the article read.
Questions over the true ages of the 35,000 unaccompanied refugee minors who registered for asylum in Sweden last year have been bubbling away in the background since long before the number of new arrivals into the country exploded in August. But it took the murder of social worker Alexandra Mezher by one of the youths for the question to be aired in international media.
Sweden's authorities have responded fast: The week after Mezher's stabbing, Sweden's migration minister Morgan Johansson called on the Migration Agency to "develop new methods to better assess age," calling for "a heightened level of ambition."
The opposition Moderate Party had already gone further, calling last year for mandatory medical age assessments for all youth refugees, something the Migration Agency, overwhelmed by the numbers coming in since August, had stopped carrying out.
Alsaudi's photo was used by some media to imply Sweden was being fooled into taking in adults who claim to be children
Part of the problem is that pediatricians in the country are refusing to carry out the assessments, arguing that the state-sanctioned guidelines released in 2012 are too inaccurate.
"The currently used methods, based on X-ray for teeth and wrists, have an underlying problem with individual variation - that because of the great variation between individuals it's difficult to get a precise assessment," said Professor Anders Hjern, a pediatrics professor at Stockholm University, who has himself carried out age assessments on refugee children.
'Being the baddest country'
He argued that the insistence on medical age assessment in Denmark, Norway and Finland was partly political.
"One of policies to keep refugees away from your country is to be the baddest country in the block. So they can say, 'we're not afraid of using these methods, even though we know they are really poor, because you don't want you to come here.'"
But even he admitted that many unaccompanied minors in Sweden were older than they claim, mainly because under Swedish law, asylum-seekers under the age of 18 cannot be sent back to their home countries unless a parent or guardian can be identified.
"It's obvious that there are strong incentives for saying that you're younger than 18," he said. "Everyone who has been involved in this for some time has heard about cases where young people have after a while admitted that they lied."
1930s US standard
But as is made clear by the case of Saad Alsaudi, the 14-year-old jogger whose picture incensed the Daily Mail, you cannot go on appearance any more than you can go on wrist measurements.
Alsaudi arrived in Sweden from Iraq at the age of six in 2003, along with the rest of his family, and a full set of valid identity papers.
"The whole family already had a permanent residence permit. There was no reason for us to lie about my age," he told Kristianstadsbladet, which took the original picture in 2012. He was four to five years older than the children in the photo, taken when he returned, aged 14, to his old school to encourage pupils to take up athletics.
"It's extremely difficult to assess age in the upper teens, especially when you have young people from populations that you're not used to seeing," Hjern said. "You see populations from the Middle East, where many people have a lot more body hair that we have in Sweden, which makes them look a lot older."
That same variation between populations also affects the age determination methods recommended by Sweden's health authorities.
"The wrist has a very big problem, which is that the scale we use is based on American children in the 1930s, and there are many indications it's not correct in the age segment we are talking about," Hjern said. Dental maturity presents similar problems. "It seems Asian populations have a later maturity with the wisdom teeth, and African populations have an earlier maturity," he added.
Ethics of medical age determination
Sweden's National Board of Health and Welfare is now carrying out a study of the most up-to-date methods of medical age assessment, particularly assessing the MRI scans developed by the international soccer body FIFA to check players are under 17, which they believe can bring down the margin of error.
"From the findings of our systematic review of the scientific literature we think that plus or minus one year is the range of uncertainty using MRI examinations," said Lars-Torsten Larsson, director of Department for Knowledge-Based Policy of Health Care at Sweden's National Board of Health and Welfare. "Of course all the different aspects, ethnical differences, gender differences, differences because of starvation and other things will be considered also in the expert review."
As well as MRI scans, the board is looking at more advanced dental techniques and using computers which can run complex algorithms combining a range of different measurements to reduce uncertainty. The study, the findings of which will be announced at a conference in April, is also assessing the ethics of medical age determination.
"Who is it beneficial for? Is it for the benefit of the person? There are ethical conflicts regarding that," Larsson said, adding that some doctors were undoubtedly also repelled by the echoes of the race biology research of the 1930s.
Hjern believes that even the most improved and up-to-date assessment will probably fall short.
"Because of individual variation, it's probably impossible to have a really precise method of assessing chronological age," he said.
Instead, he thinks Sweden should adopt the "psycho-social" methods used in the UK, when psychological experts assess age through observation and interviews, arguing that at least what is being measured, even if it doesn't accurately determine chronological age, is revelant to how asylum seekers are treated.
"They're trying to assess the maturity of the person so they go to the right place in the refugee reception system - so if they are not mature they won't be put into a situation that they can't handle, whether they are 16 ,17, 18 or more."
The Swedish Council on Health Technology, another agency, has been tasked with examining this, and Johansson, the migration minister, has also expressed an interest.
But Larsson believes that in a country where everyone has their date of birth embedded in their personal ID number - the key to accessing almost all services and to which all personal data is pinned, chronological age assessment is essential.
"Housing, schooling and a lot of other things we have in Sweden are all based on age. There are a lot of differences in legislation on how society treats you if you are above or below 18."