Is It Time to Reject the Friendly Polygraph Examiner Hypothesis (FPEH)?

Charles R. Honts

Boise State University

Paper presented at the meetings of the American Psychological Society

24 May 97, Washington, D.C.

Background

The Friendly Polygraph Examiner Hypothesis (FPEH) is a notion that was first described by Orne (1975). The FPEH suggests that polygraph examinations conducted for the defense on a privileged and confidential basis are more likely to produce false negative outcomes than when subjects know that the examiner will report adverse outcomes. The FPEH assumes that if the subject expects that only a favorable outcome will be reported, the subject will have little at stake and will have no fear of the detection of deception. This lack of fear of the detection of deception will reduce the threat posed by the crime-relevant questions in the polygraph examination and the guilty subject will be more likely to pass.

Since Daubert v. Merrill Dow Pharmaceuticals, Inc. (1993), the issue of the admissibility of polygraph has again become an open issue in U. S. courts of law (McCall, 1996). The FPEH is one of the main objections raised by prosecutors (Raskin, 1986), scientific critics of polygraph testing (e. g., Iacono & Lykken, in press) and by some law enforcement agencies (Murphy, 1996) to the admission of defense offered polygraph tests. Legal rulings in the U.S. are currently mixed with regard to the validity of the FPEH, with some courts finding it to be without validity (e. g., U. S. v. DeLorean, 1984; U. S. v. Galbreth, 1996) and other courts finding it compelling (U. S. v. Caillier, 1996). The present effort analyzes the FPEH by three methods: a logical analysis of the assumptions and conclusions of the FPEH, a review of the published scientific literature, and finally through new data from confidential and non-confidential field cases.

The Comparison Question Test

Most polygraph tests conducted for forensic purposes use some variant of the comparison (control) question technique (CQT). There are two active elements in a CQT: Relevant Questions which deal directly with the matter under investigation (e.g., Did you shoot John Doe?) and Comparison Questions to which the subject is either directed or maneuvered into lying (e.g., Before 1996, did you ever do anything that was dishonest or illegal?). The rationale of the CQT requires differential responding between these two active elements. Guilty subjects are expected to respond more to relevant than to comparison questions while innocent subjects are expected to respond more to comparison than to relevant questions. Equivalent response to both the relevant and comparison questions results in an inconclusive outcome.

Logical Analysis

Two basic assumptions underpin the FPEH: (1) Fear of the detection of deception is necessary for the CQT to function. (2) There is no fear of detection of deception (or other motivation) in a confidential polygraph examination.

First, there is no basis for assuming that fear of the detection of deception is necessary for the CQT to function. Physiological detection of deception has been demonstrated in numerous laboratory studies under no motivation, reward motivation, punishment and even when the subjects did not know they were in a detection of deception situation (see the review by Steller, 1986). No differences between these motivational conditions has been reliably observed. Although fear may be sufficient for the detection of deception it clearly is not necessary. Fear is not an important part of any modern theory of CQTs.

Even if fear were necessary for detection, it does not follow that a reduction in fear would allow a deceptive person to pass the test. The CQT requires differential reactivity between relevant and control questions. A reduction in fear would reduce the fear associated with both question types thus maintaining the differential reactivity between the two. Since these tests are evaluated within-subjects, and not against a normative standard, the effect of reducing the motivation level (fear) would be nil.

Finally the FPEH's assumption that there is no fear (or any motivation) in a confidential polygraph is unrealistic. The subject of a confidential polygraph in criminal case has a clear motivation, the gain she or he will receive from passing the test. Clearly this is a more powerful motivation than the small monetary rewards used in most laboratory studies.

Validity in the Laboratory

If the FPEH were correct, then one would expect that laboratory studies of the CQT, run under conditions that do not include negative sanctions associated with deceptive outcomes, to produce a large number of false negative errors. This is clearly not the case. The present analysis reviewed 16 laboratory studies of the CQT (see Table 1). None of which contained negative consequences for failing the examination. Those studies included 457 guilty subjects and 361 innocent subjects. Over all of the studies, the false negative rate was 11.00% while the false positive rate was 16.63%. This outcome is the opposite of the prediction generated by the FPEH. Notably, five of the 16 studies reported no errors with guilty subjects, despite a lack of fear or any negative sanctions associated with failing the test.

Table 1. Outcomes of Laboratory Studies of Comparison Question Tests

Study	Guilty Subjects				Innocent Subjects
	n	% Correct	% Wrong	% Inc.	n	% Correct	% Wrong	% Inc.
Barland & Raskin (1975)	36	64	8	28	36	42	16	42
Barland & Honts (1990)	20	70	25	5	20	70	20	10
Dawson (1981)	12	100	0	0	12	75	17	8
Honts & Barland (1990)	44	86	9	5	44	41	25	34
Honts et al. (1985) Exp. 1	12	59	8	33	12	50	17	33
Honts et al. (1985)1 Exp. 2	19	89	0	11	19	42	21	37
Honts et al. (1987)1	10	80	0	20	10	70	20	10
Honts et al. (1994)1	20	70	20	10	20	75	10	15
Horowitz et al. (1997) 2	15	53	20	27	15	80	13	7
Kircher & Raskin (1988)	50	88	6	6	50	86	6	8
Otoole et al., (1994)	64	58	23	19	16	50	25	25
Podlesny & Raskin (1978)	20	70	15	15	20	90	5	5
Podlesny & Truslow (1993)	72	69	13	18	24	75	4	21
Raskin & Hare (1978)	24	88	0	12	24	88	8	4
Rovner et al. (1979)1	24	88	0	12	24	88	8	4
Szucko & Kleinmuntz (1981)	15	71	29	0	15	49	51	0
Means	457	75.19	11.00	13.81	361	66.94	16.63	16.44

¹Countermeasure subjects excluded.

² Traditional Control Question subjects only.

Data From Actual Cases

An exhaustive sample of field case data from an experienced polygraph examiner who conducted both confidential and non-confidential polygraph examinations was examined. Between January of 1983 and April of 1997 this examiner conducted 110 confidential and 40 non-confidential polygraph examinations that resulted in a decision. If the FPEH were correct, then the percentage of subjects passing the polygraph should be much higher in the confidential than in the non-confidential tests. This was not the case, 56.30% of the confidential tests were passed, while 70.00% of the non-confidential tests were passed. This is not different than chance c² (1) = 0.15, ns, but the trend in the data is in the opposite direction of that predicted by the FPEH.

Conclusions

• The FPEH does not make sense in the context within which confidential comparison question tests are actually conducted.

• Predictions of the FPEH find no support in laboratory data where the effects should be the strongest.

• Predictions of the FPEH find no support in field data of confidential and non-confidential comparison question tests.

The Friendly Polygraph Examiner Hypothesis is completely without logical or empirical support and should be abandoned as a reason for opposing the use of defense offered of polygraph examination in courts of law.

Posted Online on 1 June 1997

Number of page accesses since 1 June 1997:

Return to the Polygraph Law Resource Page

Return to the BSU Department of Psychology Electronic Journals Page

This page created and maintained by Charles R. Honts, Ph. D.