A Parrot Or A Lie Detector?
‘We Admonish The Witnesses’
(Sanhedrin 29a)
The Mishnah states that when interrogating witnesses, we should bring them into a room and instill fear in them. What if witnesses have not undergone this treatment? What if they are not even human?
When a woman has received a warning (kinuy) from her husband, he must divorce her if he later learns that she secluded herself with this man again. R. Yehoshua says two witnesses to this seclusion are required. R. Eliezer disagrees, maintaining that “even if he heard from a flying bird, he must divorce her and give her a kesubah” (Sotah 31a).
Unusual Testimony
Rashi (s.v. afilu) explains that R. Eliezer means we accept testimony in this instance even from a slave or a relative, even though normally their testimony is invalid. The Rambam (in his commentary on the Mishnah) offers a more literal explanation – that the husband learns of his wife’s seclusion from a bird chirping. The Tiferes Yisrael interprets “a flying bird” to be a papagia (parrot). We assume that if a parrot reports the wife’s seclusion, it is mimicking words it overheard from a person.
Not Relying On Lie Detectors
After the invention of the polygraph, commonly known as the lie detector, litigants in court cases often asked dayanim to use this device to verify their claims. Can beis din force a defendant to undergo a polygraph test? What if someone voluntarily took the test and the results showed he was not lying? Can a beis din rely on it? To answer this question, we must understand how a polygraph works.
How A Polygraph Works
A person taking a polygraph test has a pneumograph tube fastened around his chest, a blood pressure-pulse cuff strapped around the arm, and electrodes placed on the fingers and surfaces of the hand. Pens record impulses on moving graph paper, and these parallel graphs are then correlated and interpreted to determine whether the subject is lying. When a person lies, certain body changes occur: he swallows his saliva, his mouth goes dry, his blood pressure rises, he sweats and blushes, he avoids looking straight in the interrogator’s eyes, and when he finishes lying a sigh of relief can be discerned. For most people, the physiological phenomena recorded are not subject to voluntary control, and this test is 80-95 percent successful in determining whether a person under interrogation is lying.
Experts say the results are not based solely on what the machine records. They also take into account the investigator’s personal observations of the subject during the test and beforehand during the preliminary interview. Also factored in is background information on the subject that the interrogator receives from others.
In light of all the above, poskim (Tzitzis Eliezer 16:47 and Ba’er Moshe 7:79) have ruled that since the results of the polygraph test do not unequivocally show whether a person is lying, and since they are partially based on the examiner’s subjective analysis and impressions, the results are considered an “estimation upon an estimation,” which is not considered halachically reliable.
The Gemara (Shavuos 34a) relates that Shimon Ben Shetach saw a person running after another person into an abandoned house. Shimon Ben Shetach ran after them and saw the pursuer holding a sword dripping with blood, and the one he had been chasing was mortally wounded and bleeding profusely. Nonetheless, it was impossible to declare with certainty that the pursuer was the murderer, and Shimon Ben Shetach’s testimony was only considered an “estimation.” Certainly the same is true of polygraph test results for monetary matters and cases of gittin and kiddushin.
A Lie Detector 2,800 Years Ago
Rabbi Eliezer Waldenberg, zt”l (Tzitzis Eliezer, ibid.), writes, “Who is greater for us than Shlomo HaMelech, the wisest of all men, who wanted to rule monetary affairs even without witnesses? (Rosh Hashanah 21b).” The Zohar (Parashas Yisro 78a) relates that Shlomo in his great wisdom invented a lie detector that he connected to his throne: “When anyone would touch it and lie, the animals figures on his throne would shake and Shlomo would know he was lying.” The Gemara (ibid.) tells us that a bas kol was heard, announcing that we cannot make decisions based on the movements of Shlomo’s throne. Only the testimony of two kosher witnesses can be accepted.