Medicine: Blood Will Tell

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In most states when a man is accused by an unmarried woman of having fathered her child, the judge must play Solomon; with a jury, there may be as many as 13 Solomons. Kentucky is one of the states where blood-test evidence is admissible, but not binding, and in Chicago last week Dr. Malcolm L. Barnes, 47, told the American Society of Clinical Pathologists how well the system works in Jefferson County (Louisville and environs).

The blood group (A, B, AB and O) tests cannot prove paternity, nor can they disprove it in every case, said Pathologist Barnes. If the tests of mother's and baby's blood indicate that the father's must be type A, the father could still be any man with type A. But that decisively acquits the 60% of men who have B, AB, or O blood.* Besides the ABO grouping of red cells, blood varies according to whether it contains a factor M (present in 30% of the population), N (in 20%), or both, MN (in 50%). Blood also is classified according to which of the 27 subgroups of the Rh factor it belongs. Even with the tests' present limitations, Dr. Barnes proudly reported, in 39 cases this year he has exonerated eight accused men by the test itself, while six more men went free because the complaining mothers dropped their charges as soon as they heard the court order a blood test. Medical science eventually will make the test far more discriminating. Dr. Barnes believes. When tests for these factors are simplified so that they can be done in any pathology laboratory, the chances for a scientifically proved verdict in paternity cases should be increased.