Deportation and genetics: Fairness and probabilities

Wednesday, August 1, 2018
by Cameron Shelley

Vicky Mochama notes that the Canadian Border Services Agency (CBSA) has been using genetic testing to determine where to deport certain would-be migrants to Canada

In some cases, the national background of some would-be migrants to Canada can be difficult to establish, say, due to a lack of formal records or political disruption.  In such cases, the CBSA has a hard time determining where to deport people turned down for admission.  This difficulty can result in people being held in detention for years although they have committed no crime under Canadian law.

In some of these cases, the CBSA has turned to commercial genetic testing services such as  These services can provide users with heritage reports, suggesting where in the world some of their ancestors lived based on patterns in the geographic distribution of certain genetic variations.  Although these reports are typically presented as for "recreational" purposes only, it seems that CBSA has been taking them as positive evidence of nationality.

Mochama explains a number of ways in which this policy is problematic.  For one thing, the geographic location of some of your ancestors is not a guaranteed indication of nationality.  After all, many of my ancestors were from Britain but I am not a British citizen.

Also, the information for these reports is particularly spotty for some geographic regions.  Genetic patterns among people in African nations are particularly poorly understood.  So, genetic reports on African ancestry are particularly likely to be misleading or wrong.  Yet, it is precisely such places for which the CBSA is often seeking clarification.

Consider a third objection.  Correlations between geographic regions and genetic ancestry apply to populations.  For a variety of reasons, human populations from different regions have characteristic pattens of genes. Yet, individuals from any given region may lack any given genetic trait typical of the regional population.  Furthermore, individuals from other regional populations may possess such traits. 

As a result, even if a migrant has DNA known to be characteristic of a given nation (a big if), such an assignment is only probabilistic and never definitive.  As such, any policy of deportation based on genetic tests will deport a certain percentage of people to the wrong destinations. 

This raises the question: What level of certainty would justify deportations under these conditions?  No system works perfectly but one that works haphazardly would hardly be just or fair.  No report suggests that the CBSA has identified an appropriate level of certainty or verified that the recreational ancestry reports that it relies on meet this standard. 

Until these issues are addressed, this practise can hardly be considered a fair one.