A Conservative MP has called for a ban on cousin marriages. His proposed bill is unlikely to proceed further without government backing. His main argument is that the risk of birth defects doubles among marriages to first cousins. He also argues that cousin marriages ‘reinforce negative structures and control women’.

Although this is not my main field, this is a really interesting topic. This is essentially an issue concerning the 1.5 million Pakistani community, who comprise 2.7% of the population of England & Wales.

The ‘Born in Bradford’ cohort study looked at 11,396 babies born in the Bradford area between 2007 and 2011. Altogether 18% of babies were born to first cousin marriages, almost all of which (95%) were Pakistani families. Cousin marriages represented one third (37%) of the Pakistanis parents (Sheridan, 2013).

Among this cohort, 3.1% of babies were born with congenital anomalies compared to a national rate of 1.7%. Consanguinity – as cousin marriage is known – was associated with a doubling of risk. Although it would be easy to claim that this is actually about poverty, this study found no association with deprivation. This is clearly a link with cousin marriage.

There is plenty of research on why cousin marriage especially effects the Pakistani community. Part of the reason is transnational marriage where a British Pakistani married their cousin abroad to give them ‘a better life’ (Shaw, 2014). However there is clearly a cultural issue involved where this is an accepted way of life. In Muslim societies, up to half of all marriages involve cousins. Despite the birth risk, there are considerable advantages from the point of view of family cohesion, economic cooperation, and less early marriage of girls (Al-Shafaee, 2023).

In a global review of cousin marriage, Nash (2024) argues that the evidence on birth defects is limited by the need to extrapolate from small-scale studies or large-scale local ones. There is no national data available. He also points out that few scholars have reached clear conclusions despite a great deal of research. This issue crosses many divides, to the extent that the Law Commission were banned from considering it in a review of marriage law.

What do I think? I think we should tread very carefully on this. It is not a black and white issue. Marriage is already banned between siblings, parents and children. Domestic violence and coercive control are also illegal. This is an issue that primarily affects the Pakistani community. The problem of birth defects is real but fairly marginal. Its not like FGM where children are actively being abused. This is an issue that improves economics and cohesion for most families but negatively and unintentionally affects a small minority of children.

There is also the problem of enforceability. Banning cousin marriage would be hard, if not impossible, to police. Many, possibly most, Pakistani cousin marriages are transnational. Would these marriages simply not be recognised? When children are born, would the parents go to jail? The simplest way to avoid a marriage ban is for the parents not to marry legally. After all, half of British children are already born to unmarried mothers and the British fiscal system does not differentiate between married and cohabiting couples.

If we want to do something about marriage, we should be encouraging, not discouraging, it. The trend away from marriage is the reason we have the highest level of family breakdown in recorded history. That’s the real injustice affecting half of all our children in all our communities, not just a very small number from one group. That’s where MPs should really focus their energies.