There is a 2-5% chance of non-paternity every generation, therefore, if you go back far enough, the odds of having a non-paternity event is very likely. The non-paternity rate relates to where a child has a surname which is not from his biological father. This genetic break can be for a number of reasons, e.g. illegitimacy; adoption. The effect is cumulative over generations. As an example, if you go back 10 generations there is a 20-50% chance of this occurring. This is why it is essential to test more than just one person from each line. Importantly, non-paternity rates vary in different socio-economic groupings, so these need to be considered in any calculation. More than 250,000 paternity tests a year are now conducted in America, and about 15,000 in the United Kingdom. Roughly 30% of men taking the tests discover that they are not the fathers of the children they regarded as their own. In the wider community, social scientists say up to 1 in 20 children are not the offspring of the man who believes himself to be their father (Sunday Times, 11.6.2000). Physicians, doing tissue typing for organ donations, estimate that maybe 20% of people are not genetically related to the men who claim fatherhood; others say it is less, perhaps as low as 5% (Rothman, 1989). The consultant obstetrician E. E. Phillipp reported to a symposium on embryo transfer that blood tests on between 200 and 300 women in a town in the south-east of England revealed that 30% of their children could not have been fathered by the men whose blood groups had also been sampled (The Guardian, 14.7.1998). The Child Support Agency in the UK calculates that 10% of children will have ‘surprising paternity’ (Pearson, 2000).

 

References

Pearson, B. (2202) "Knowledge is bliss"- Towards a society without paternity surprises. http://www.childsupportanalysis.co.uk/papers/knowledge/evidence.htm

Rothmam, B.K. (1989) Recreating Motherhood: Ideology and Technology in a Patriarchal Society.

Home