Receiving the results of a paternity test is a moment filled with anticipation, and understanding what do paternity test results look like helps remove uncertainty. Modern DNA analysis provides a clear and scientific answer that was not possible just a couple of decades ago. The document you receive is more than a simple piece of paper; it is a legal and biological report that outlines the statistical probability of a biological relationship. This guide walks through the structure, science, and legal considerations of the report you will receive.
Understanding the Science Behind the Document
The foundation of any paternity test is the comparison of genetic markers. Each person inherits half of their DNA from their biological mother and half from their biological father. The testing laboratory examines specific locations on the chromosomes, called Short Tandem Repeats (STRs), to identify these inherited markers. By comparing the DNA profile of the child with the alleged father, the lab can determine how many genetic markers match. The results you see quantify this comparison, translating the raw data into a probability score that reflects the likelihood of a biological relationship.
The Role of the Combined Paternity Index (CPI)
One of the most critical numbers on the document is the Combined Paternity Index (CPI). This figure is calculated by multiplying the results of each tested genetic marker. Essentially, the CPI compares the likelihood of observing the child’s genetic markers if the tested man is the biological father versus if he is not. A high CPI indicates a strong genetic match. For example, a CPI of 10,000 means the tested man is 10,000 times more likely to be the biological father than a random man from the same population.
Decoding the Probability Percentage
Most people looking at a report want to see a single, clear answer, which is usually presented as a percentage. This percentage represents the probability that the alleged father is the biological parent. In the vast majority of reputable tests, a result of 99.99% or higher is considered conclusive proof of paternity. Conversely, a result of 0% indicates that the tested man is not the biological father. Results that fall into a very narrow grey zone, usually below 50%, are typically classified as inconclusive, meaning the test failed to establish a relationship.
Reading the Actual Table
The data is often presented in a table format that might look complex at first glance, but it is straightforward to interpret. The table lists the specific genetic markers tested, the numbers assigned to the child and the alleged father, and whether they match. If the numbers align, it confirms inheritance from the father. A mismatch in too many locations would suggest a lack of biological relation. Below is a simplified example of how these results are typically displayed.
