Can a Polygraph Be Considered as Sufficient Evidence to Begin an Investigation?

A polygraph test, also known as a lie detector test, is a device designed to measure and record physiological responses in an individual to determine whether they are lying. While widely used in law enforcement and corporate security, the accuracy and effectiveness of polygraph tests have been heavily contested.

Theoretical Basis and Scientific Validity

The reliability of polygraph tests is often debated among experts and scientists. According to the consensus view among scientists, polygraph testing has no scientific basis. This is a significant limitation, as the results of a polygraph test cannot be used as conclusive evidence in legal proceedings.

It's important to highlight that the Federal Bureau of Investigation (FBI) and the Central Intelligence Agency (CIA) have their own perspectives on the polygraph. For instance, the creator of the lie detector test was once seen as a phony and a crackpot. Furthermore, the man who established the CIA’s polygraph program had a rather fantastical belief that plants could read human thoughts, which is not supported by any scientific evidence.

Education and Advocacy

Despite the scientific discredits, many organizations continue to offer polygraph training. The longest polygraph school can generate newly minted polygraphers in just 14 weeks, which is significantly shorter than the time it takes to graduate from a typical barber college.

The National Center for Credibility Assessment, derived from the DoD Polygraph Institute, performed a study that was ultimately suppressed, which suggested that innocent blacks are more likely to fail the polygraph than innocent whites. This raises questions about the fairness and reliability of polygraph tests, especially in diverse communities.

Historical and Contemporary Implications

The use of polygraphs in espionage and intelligence gathering is another controversial area. The National Academy of Sciences has concluded that spies have successfully passed polygraph tests, including notable cases like Ignatz Theodor Griebl, Karel Frantisek Koecher, and Aldrich Hazen Ames. This inconclusiveness highlights the limitations of polygraph tests in real-world applications.

One of the most prolific serial killers in U.S. history also passed the polygraph test and continued to commit murders. This juxtaposition with the innocent suspect who failed the test underscores the unreliability of polygraph results.

Furthermore, organizations such as Al-Qaeda and Iraqi insurgents are well aware that the lie detector is a flawed tool and do not rely on it for decision-making.

Conclusion

In summary, while polygraph tests may seem like a convenient tool for investigation, they are not reliable evidence in any legal or ethical context. The failures and biases highlighted in various studies and real-world applications demonstrate that polygraph results should not be trusted as conclusive evidence. Law enforcement and other professionals who use these tests must consider these limitations and seek more robust methods of verifying information.