Legal Definitions - blood-grouping test

A blood-grouping test is a scientific examination of blood samples used in legal proceedings, primarily those concerning parentage, to determine if a biological relationship exists between individuals. The fundamental purpose of this test is to ascertain whether a specific individual could not possibly be the biological parent of a child.

It is crucial to understand that a blood-grouping test does not definitively establish paternity or maternity on its own. Instead, its primary function is to exclude individuals who cannot be the biological parent. If a person's blood type or genetic markers are incompatible with those of the child and the known parent, that person is definitively ruled out as the biological parent. If they are not excluded, it means they *could* be the parent, and this evidence, often combined with other factors, helps courts make a determination.

• Example 1: Child Support Claim

  Imagine a situation where a mother files a lawsuit seeking child support from a man she identifies as the child's father. The man disputes paternity. The court might order a blood-grouping test for the mother, child, and the alleged father. If the test results show that the man's genetic markers are incompatible with the child's, he would be scientifically excluded as the father, likely leading to the dismissal of the paternity claim against him. Conversely, if he cannot be excluded, this evidence would strongly support the mother's case, moving towards a potential child support order.

• Example 2: Inheritance Dispute

  Consider a scenario where a wealthy individual dies without a will, and a person comes forward claiming to be their previously unknown biological child, seeking a share of the estate. Other family members, who stand to inherit, challenge this claim. To resolve the dispute, a court could order a blood-grouping test. If samples from the deceased are unavailable, tests might be conducted comparing the claimant's blood with that of the deceased's proven biological relatives (e.g., parents or other children). If the test results definitively exclude a biological relationship between the claimant and the deceased's lineage, the inheritance claim based on biological parentage would be denied.

• Example 3: Immigration and Citizenship Verification

  An individual living abroad applies for citizenship in a country, asserting that they are the biological child of a citizen already residing there. Immigration authorities, needing to verify the claimed familial relationship for citizenship purposes, may require a blood-grouping test between the applicant and the alleged parent. If the test results indicate that the alleged parent cannot be the biological parent of the applicant, the citizenship application based on that specific familial tie would likely be rejected due to the lack of a proven biological connection.