Pretend that someone develops a genetic test for sociopaths. To test the test researchers look at 100 sibling pairs, and for each pair one but not both siblings have been diagnosed as sociopaths. The genetic test, let's assume, does extremely well in identifying the sociopaths. Would you claim that this result is, as you say, "highly subject to interpretation"?
People would assuredly argue about whether whatever definition of sociopath being used was describing something real.
I wrote an article for h+ predicting that the rapid fall in the cost of gene sequencing will allow U.S. voters to learn much about presidential candidates' DNA. The candidates won't be able to stop this because:
DNA analysis has a decent chance of reducing political bias by providing objective information about candidates. If, for example, 70% of the variation in human intelligence is determined by identified genes then DNA analysis would reduce disagreements among informed voters over a candidate's intelligence.