Siblingship test
A Siblingship test is intended to determine whether two people are siblings (brothers and sisters). There are issues with this kind of test, though. While a result with a paternity test is incredibly accurate, Siblingship tests aren't always as reliable – because tests often have to be conducted differently.
Many people who pursue Siblingship tests don’t have access to samples of their parents DNA. With a paternity test the DNA of the child and the father are matched up easily and results are either positive or negative.
However, with a Siblingship test, because siblings have a diverse mix of both their mothers and father’s genes a special Siblingship index has to be created which provides a score–based result that reports on the likelihood of the two people being related.
Instead of being a positive or negative result, the people who have their Siblingship tested are given a number, if that number (which reflects the amount of similarity between their DNA samples) is lower than 1.00 then they aren’t related to each other and if it’s above 1.00 it means the two people are more likely to be siblings.
The more DNA patterns two people share, the more likely it is they have the same parents. If it’s believed that the siblings only share one parent, then a half–sibling index is created instead. The accuracy of a Siblingship test can be improved if the DNA of one (or both) of the parents can also be tested and an even more fool–proof way to determine whether two people are siblings is to compare their DNA to that of both parents.
