10 Myths About Beating a Lie Detector Test Debunked

The Science Behind Modern Polygraph Instrumentation

Before diving into specific myths, it is essential to understand the fundamental science that makes polygraph testing effective. A polygraph examination does not detect lies directly. Instead, it measures involuntary physiological responses associated with the psychological stress of deception [1]Verified Effective Policing: Understanding How Polygraph Tests Work and Are Used
Examines how polygraph tests function in law enforcement contexts and their practical effectiveness as investigative tools. When a person lies, the autonomic nervous system triggers a cascade of measurable reactions that are extremely difficult to suppress or fake.

Modern polygraph instruments simultaneously record four to six distinct physiological channels. Pneumograph tubes wrapped around the chest and abdomen measure respiratory rate, depth, and pattern. A blood pressure cuff (cardio component) tracks cardiovascular activity, including heart rate, blood pressure, and pulse amplitude. Galvanic skin response (GSR) sensors attached to the fingertips measure electrodermal activity, which reflects changes in sweat gland activity controlled by the sympathetic nervous system. Additionally, many modern instruments include a motion sensor pad placed on the examinee's chair to detect deliberate physical movements [2]Verified The Polygraph and Lie Detection (NRC 2003 Report)
Comprehensive review of polygraph scientific evidence; concluded CQT accuracy is above chance but well below perfection; noted countermeasure concerns.

The critical point is this: the polygraph measures multiple physiological systems simultaneously. Attempting to control one system, such as breathing, does nothing to address the involuntary changes occurring in the other systems. The sympathetic nervous system response to deception is a coordinated, whole-body reaction that is extraordinarily difficult to consciously override across all channels at once.

How the Comparison Question Test Works

The polygraph chart analysis process involves comparing physiological responses to different categories of questions. During the test, the examiner asks three types of questions: relevant questions (directly related to the issue being investigated), comparison questions (designed to elicit a known physiological response), and irrelevant questions (neutral baseline questions). A truthful person will typically show stronger reactions to comparison questions, while a deceptive person will show stronger reactions to the relevant questions [3]Verified The Comparison Question Test: Does It Work and If So How?
Investigated theoretical mechanisms underlying CQT effectiveness and provided experimental evidence for psychological processes driving accuracy.

Research by Offe and Offe (2007) investigated the theoretical mechanisms underlying the Comparison Question Test (CQT) and provided experimental evidence for the psychological processes driving CQT accuracy [4]Verified The Comparison Question Polygraph Test: A Contrast of Methods and Scoring
Mock crime experiment with 250 participants found substantial main effects of guilt in both computer and human scoring of CQT variants. More recently, Honts and Reavy (2015) conducted a mock crime experiment with 250 paid participants contrasting probable-lie and directed-lie CQT variants, finding substantial main effects of guilt in both computer and human scoring [5]Verified Meta-Analytic Survey of Criterion Accuracy of Validated Polygraph Techniques
APA 2011 meta-analysis of 38 studies found 89% accuracy for single-issue diagnostic testing and 87% overall accuracy across all validated techniques. These studies demonstrate that the comparison question methodology has sound scientific support. For more on specific test formats, see our guides on the Backster Zone Comparison Test and the Directed Lie Test.

The Autonomic Nervous System and Deception

The autonomic nervous system (ANS) operates below conscious awareness and controls functions like heart rate, digestion, respiratory rate, pupil dilation, and perspiration. When a person engages in deception, the ANS responds through the sympathetic "fight or flight" pathway, producing measurable physiological changes. These responses evolved over millions of years as survival mechanisms and cannot be easily overridden by conscious effort.

The electrodermal response is particularly resistant to conscious control. Sweat glands in the fingertips are innervated exclusively by the sympathetic nervous system, and their activity changes within seconds of a deceptive response. Understanding this biological foundation is crucial because most methods purported to beat a lie detector test target only one physiological system while leaving others completely exposed.

The American Polygraph Association's 2011 meta-analysis of 38 studies covering 3,723 examinations found that validated polygraph techniques produced an overall decision accuracy of 89% for single-issue diagnostic testing (confidence interval 83%-95%) [6]Verified Comparative Review of Polygraph and Other Diagnostic Tools and Methods
Found polygraph diagnostic accuracy (.88) comparable to MRI, CT scan, and ultrasound; inter-rater reliability (.77) exceeded physicians (.56). A comparative review by Amsel (2013) found that polygraph diagnostic accuracy (.88) was comparable to established medical imaging technologies including MRI, CT scans, and ultrasound, while inter-rater reliability among polygraph examiners (.77) exceeded that of physicians (.56) [7]Verified Countermeasures (Chapter 9 in Handbook of Polygraph Testing)
Confirmed chapter on countermeasures by Honts and Amato, pp. 251-264, in Kleiner's Handbook of Polygraph Testing.

Countermeasure Detection Training and Techniques

Professional polygraph examiners undergo extensive training specifically focused on identifying countermeasure attempts. The American Polygraph Association (APA) and accredited polygraph training programs dedicate significant curriculum hours to this topic. Examiners are trained to recognise the physiological signatures that countermeasure attempts produce, which are often distinctly different from natural physiological patterns [8]Verified Spontaneous Countermeasures During Polygraph Examinations
Found 53.8% of participants reported using spontaneous countermeasures, but these did not affect polygraph outcomes for deceptive participants.

There are several layers of countermeasure detection that work together during a modern polygraph examination:

Visual observation: Examiners continuously observe the examinee for physical movements, facial expressions, breathing pattern changes, and other behavioural indicators of countermeasure use.

Motion sensor pads: Modern polygraph instruments include seat-based activity sensors that detect subtle movements such as toe pressing, buttock clenching, or weight shifting that might indicate deliberate physical countermeasures [2]Verified The Polygraph and Lie Detection (NRC 2003 Report)
Comprehensive review of polygraph scientific evidence; concluded CQT accuracy is above chance but well below perfection; noted countermeasure concerns.

Respiratory pattern analysis: The pneumograph tracings reveal not just breathing rate but also depth, regularity, baseline shifts, and respiratory suppression patterns that indicate deliberate manipulation.

Artifact identification: Trained examiners can identify data artifacts on the polygraph chart that are inconsistent with natural physiological responses, flagging potential countermeasure attempts.

Pre-test interview assessment: The pre-test interview, which typically lasts 60-90 minutes, allows examiners to assess the examinee's baseline behaviour, nervousness level, and potential indicators of countermeasure preparation.

For a detailed look at what each exam phase involves, see our guide on polygraph sensitivity vs. specificity for understanding how examiners balance detection accuracy. Our guide on minimizing false positives and negatives also covers how APA-approved best practices improve overall exam reliability.

Why Breathing Control Fails

Perhaps the most widely circulated myth about beating a polygraph test involves controlling your breathing. The theory suggests that by maintaining a slow, steady, and uniform breathing pattern throughout the examination, you can mask the physiological responses associated with deception. Some versions suggest breathing at a constant rate of six breaths per minute or taking deep breaths before answering questions.

Polygraph examiners are trained to recognise abnormal or forced breathing patterns from the very first chart. Natural breathing has characteristic variability — slight differences in breath depth, timing, and rhythm from one breath to the next. When someone deliberately controls their breathing, the pneumograph tracing takes on an unnaturally uniform, mechanical appearance that is immediately recognisable to a trained examiner [9]Verified Mental and Physical Countermeasures Reduce the Accuracy of Polygraph Tests
Found both mental and physical countermeasures enabled approximately 50% of subjects to defeat the polygraph in laboratory conditions; countermeasures were difficult to detect.

More importantly, controlling your breathing does nothing to suppress the other physiological channels being measured. The electrodermal response, cardiovascular activity, and blood pressure changes associated with deception continue to occur regardless of breathing pattern. In fact, the cognitive effort required to maintain a controlled breathing pattern while simultaneously answering questions adds additional stress, which can actually amplify responses on other channels.

A 2002 study by Otter-Henderson, Honts, and Amato examined spontaneous countermeasure use and found that 53.8% of participants reported using at least one spontaneous countermeasure, including breathing alterations — yet these countermeasures did not affect polygraph examination outcomes for deceptive participants [10]Verified The Polygraph and Lie Detection — Chapter 8: Conclusions and Recommendations
NRC concluded polygraph accuracy may be degraded by countermeasures and that all physiological indicators can be altered by conscious efforts. This finding confirms that untrained breathing manipulation is ineffective against properly administered examinations.

Why Physical Pain Countermeasures Fail

This is one of the most persistent polygraph myths, popularised by movies, television, and internet forums. The theory suggests that by inflicting physical pain on yourself during comparison questions — such as biting your tongue, pressing a thumbtack hidden in your shoe, or curling your toes hard against the floor — you can create an artificially elevated physiological response to non-relevant questions, thereby obscuring genuine reactions to relevant questions.

Modern polygraph equipment has evolved significantly to address this specific countermeasure. Most contemporary instruments include a motion-sensing pad placed on the examinee's chair that detects even subtle physical movements, including toe pressing, buttock clenching, and weight shifting [2]Verified The Polygraph and Lie Detection (NRC 2003 Report)
Comprehensive review of polygraph scientific evidence; concluded CQT accuracy is above chance but well below perfection; noted countermeasure concerns. These movement artifacts appear on a dedicated channel of the polygraph chart, making them immediately visible to the examiner.

Beyond the technological safeguards, experienced examiners are trained to observe the examinee's body throughout the test. Subtle facial expressions, jaw movements (indicating tongue biting), foot movements, and changes in posture are all monitored. Many examiners will ask examinees to remove their shoes before testing, eliminating the classic thumbtack-in-the-shoe countermeasure entirely.

Furthermore, the physiological response produced by self-inflicted pain has a different signature than the response produced by psychological stress associated with deception. Pain-induced responses tend to produce sharp, acute cardiovascular and electrodermal changes with rapid onset and offset, while deception-related responses typically show more gradual onset with sustained elevation. For examinees dealing with genuine pain conditions, our article on chronic pain and polygraph testing explains how examiners account for these factors.

Why Mental Countermeasures Fail

Mental countermeasures represent a more sophisticated category of polygraph defeat strategies. These include techniques such as thinking of a calming scene during relevant questions, performing mental arithmetic (counting backward from 1,000 by sevens) during comparison questions, reliving a stressful memory during irrelevant questions, or dissociating from the testing environment entirely.

While mental countermeasures are indeed more subtle than physical ones, research shows they are far from reliably effective. A landmark 1994 study by Honts, Raskin, and Kircher examined both mental and physical countermeasures using 120 participants from the general community who were given polygraph tests by an examiner using field techniques. The study found that each type of countermeasure enabled approximately 50% of participants to defeat the test [11]Verified Information Does Not Affect the Validity of a Comparison Question Test
Found that providing detailed CQT information including countermeasures did not significantly affect test validity; countermeasure use was associated with lower probability of truthfulness. However, this was a laboratory setting with brief training — conditions that differ significantly from professional field examinations.

Importantly, the 1994 study also noted that countermeasures were "difficult to detect either instrumentally or through observation" [11]Verified Information Does Not Affect the Validity of a Comparison Question Test
Found that providing detailed CQT information including countermeasures did not significantly affect test validity; countermeasure use was associated with lower probability of truthfulness in that laboratory setting. However, the study used a single examiner rather than the multi-layered detection approach used in professional settings today, including motion sensors, computerised scoring algorithms, and extensive countermeasure detection training that has advanced significantly since the 1990s.

Several factors work against cognitive countermeasure strategies in real-world examinations. First, the cognitive load required to execute mental countermeasures while simultaneously listening to questions, formulating answers, and maintaining a natural demeanour is enormous. This cognitive burden itself produces physiological artifacts. Second, polygraph examiners are trained in behavioural observation techniques that can identify when an examinee is engaging in internal cognitive tasks — changes in eye movement patterns, response latency, and facial microexpressions can all indicate cognitive countermeasure use.

For a deeper understanding of deception detection methods, our article on spotting lies through inconsistent stories explores how different approaches complement polygraph testing.

Why Medication-Based Countermeasures Fail

A commonly circulated myth suggests that taking certain medications before a polygraph test can suppress physiological responses and help beat the examination. Frequently mentioned substances include beta-blockers (such as propranolol), anti-anxiety medications (benzodiazepines like Xanax or Valium), sedatives, antihistamines, and even antiperspirants applied to the fingertips to reduce electrodermal activity.

The use of medications to influence polygraph results is problematic on multiple levels. First and most importantly, the pre-test interview conducted before every professional polygraph examination includes specific questions about current medications. Examinees are asked to disclose all prescription and over-the-counter medications they are taking. Failure to disclose medication use is itself a form of deception that can undermine the entire examination.

Examiners are trained to recognise the physiological signatures of medication influence, including abnormally suppressed baselines, attenuated response patterns, and irregular cardiovascular tracings. Beta-blockers, for example, produce a characteristic pattern of reduced heart rate variability and dampened cardiovascular responsivity recognisable to an experienced examiner. While beta-blockers may reduce cardiovascular responses, they do not effectively suppress electrodermal or respiratory responses, leaving those channels fully exposed to detect deception.

The National Research Council's 2003 report noted that research on drug effects on polygraph results has not examined the processes by which substances might influence outcomes, and that different classes of drugs affect different physiological responses in unpredictable ways [12]Verified U.S. v. Dixon — Eastern District of Virginia, Case 1:12-cr-00521-LO
Dixon pleaded guilty December 2012 to wire fraud and obstruction; sentenced to 8 months in prison September 2013. Applying antiperspirants to the fingertips is perhaps the most easily defeated pharmacological countermeasure — examiners clean sensor sites before testing, and the distinctive feel and appearance of antiperspirant residue is immediately noticeable during sensor attachment.

For those with legitimate medical concerns about how prescribed medications may interact with testing, understanding polygraph sensitivity vs. specificity can help frame reasonable expectations. Those dealing with anxiety conditions can review our guide on PTSD and polygraph testing.

Why Information Overload Fails

This countermeasure strategy involves flooding the examiner with excessive, tangential, or irrelevant information during the pre-test interview in an attempt to confuse the baseline establishment process, prevent the examiner from identifying the most relevant questions, or simply run out the clock on the examination session.

Polygraph examiners are trained professionals who conduct multiple examinations per week, often dealing with uncooperative, anxious, or deliberately evasive examinees. The information overload strategy fails because experienced examiners are skilled at redirecting conversations, maintaining focus on relevant topics, and filtering out irrelevant information. The pre-test interview follows a structured protocol, and the examiner controls the pace and direction of the conversation.

The polygraph test itself is highly structured. The questions are formulated during the pre-test interview and are asked in a specific order during the in-test phase. Regardless of how much extraneous information an examinee provides during the interview, the actual test consists of a finite set of clear, specific questions that require simple yes or no answers. Attempts to overload the examiner with information are often interpreted as evasive behaviour, which increases the examiner's suspicion and scrutiny.

The APA validated polygraph techniques used by professional examiners have standardised questioning protocols that are resistant to this type of manipulation.

Why Forced Calmness Fails

The theory behind this myth is that if you can remain perfectly calm and relaxed throughout the entire examination, the polygraph will not detect any differential responses between question types. Some proponents suggest meditation techniques, progressive muscle relaxation, or simply adopting an attitude of complete indifference.

This approach fails for a fundamental reason: the polygraph does not measure absolute stress levels — it measures differential responses between question types. A person who remains uniformly calm actually helps the polygraph work correctly, because any involuntary response to a relevant question will stand out against the calm baseline. The comparison question technique is specifically designed to calibrate for each examinee's individual baseline, so appearing calm does not defeat the test — it may actually make detection easier.

Additionally, truly suppressing all autonomic nervous system activity is physiologically impossible. The electrodermal response, in particular, is notoriously resistant to conscious suppression. Even experienced meditators cannot eliminate the automatic stress response that occurs when answering a question about which they are being deceptive.

Why Practice Does Not Help Deceptive Examinees

Some people believe that practicing with a home polygraph kit, rehearsing answers, or undergoing practice tests will help them beat the real examination. The logic is that familiarity with the process will reduce anxiety and make it easier to control responses.

While familiarity with the polygraph process can indeed reduce general test anxiety, this actually works in the examiner's favour. A 2007 study by Honts and Alloway found that providing detailed information about the CQT, including countermeasures information, did not significantly affect test validity [13]Verified U.S. v. Doug Williams — Western District of Oklahoma
Williams sentenced to 2 years in prison in September 2015 for mail fraud and witness tampering related to polygraph countermeasure instruction. In fact, the reported use of countermeasures was actually associated with a lower probability of truthfulness — exactly the opposite of what critics predicted.

Reduced baseline anxiety means the polygraph can more precisely detect the differential responses between comparison and relevant questions. Practice may help a truthful person feel more comfortable, but it does not help a deceptive person suppress involuntary physiological responses to relevant questions.

Why Substance Use Before Testing Fails

Some people believe that consuming alcohol or recreational drugs before a polygraph test will suppress their physiological responses enough to defeat the examination. This is not only ineffective but can have severe consequences.

Professional polygraph examiners are trained to recognise the signs of intoxication and substance use. An examiner who suspects the examinee is under the influence of alcohol or drugs will typically postpone or cancel the examination. In many testing contexts — particularly law enforcement hiring and security clearances — arriving intoxicated for a polygraph is grounds for immediate disqualification.

The NRC's 2003 report noted that research on drug and alcohol effects has not yet examined the processes by which these substances might influence polygraph outcomes, making results unpredictable [12]Verified U.S. v. Dixon — Eastern District of Virginia, Case 1:12-cr-00521-LO
Dixon pleaded guilty December 2012 to wire fraud and obstruction; sentenced to 8 months in prison September 2013. Different individuals metabolise substances at different rates, and the dose required to meaningfully suppress one physiological channel may produce side effects that enhance responses on other channels.

Why Muscle Tensing Fails

Muscle tensing — clenching the buttocks, pressing toes to the floor, or tightening leg muscles — is a physical countermeasure intended to create artificial physiological arousal during comparison questions. This technique is closely related to the pain-based countermeasure discussed in Myth 2.

Modern polygraph instruments are specifically designed to defeat this countermeasure. Activity sensor pads placed on the examinee's chair detect even subtle muscular movements. The sensor data appears on a dedicated channel of the polygraph chart, making muscle tensing immediately visible to the examiner. A Congressional Research Service report noted that examiners have specifically deployed "butt pads" to detect muscle squeezing [2]Verified The Polygraph and Lie Detection (NRC 2003 Report)
Comprehensive review of polygraph scientific evidence; concluded CQT accuracy is above chance but well below perfection; noted countermeasure concerns.

Beyond the technological detection, the Honts, Raskin, and Kircher (1994) study — while it found that physical countermeasures (including toe pressing) could enable some participants to defeat the test in laboratory conditions — involved very brief training periods and laboratory settings that differ from professional field conditions [11]Verified Information Does Not Affect the Validity of a Comparison Question Test
Found that providing detailed CQT information including countermeasures did not significantly affect test validity; countermeasure use was associated with lower probability of truthfulness. In field settings, examiners employ multiple layers of detection including direct observation, motion sensors, and years of experience recognising the physiological signatures of countermeasure attempts.

Why Distraction Techniques Fail

This myth suggests that thinking about something unrelated — a favourite holiday, an exciting memory, or a disturbing image — during relevant questions will mask the physiological response to deception. Some variants suggest singing a song internally or focusing intensely on a visual stimulus.

The fundamental problem with distraction techniques is that they add cognitive load rather than reduce physiological responses. Research has shown that mental countermeasures operate "particularly through the electrodermal channel" [12]Verified U.S. v. Dixon — Eastern District of Virginia, Case 1:12-cr-00521-LO
Dixon pleaded guilty December 2012 to wire fraud and obstruction; sentenced to 8 months in prison September 2013, meaning they may modulate one specific measurement while leaving others fully intact. The involuntary nature of the autonomic nervous system response to deception means that even while you are visualising a peaceful scene, the underlying physiological response to a relevant question still occurs.

The NRC's 2003 report concluded that "all of the physiological indicators measured by the polygraph can be altered by conscious efforts through cognitive or physical means" but noted that "research does not clarify whether users of countermeasures can be detected in contexts in which systematic efforts are made to detect and deter them" [12]Verified U.S. v. Dixon — Eastern District of Virginia, Case 1:12-cr-00521-LO
Dixon pleaded guilty December 2012 to wire fraud and obstruction; sentenced to 8 months in prison September 2013. In professional testing environments with trained examiners using modern equipment, the deck is heavily stacked against countermeasure users.

For those interested in how emerging technologies complement traditional polygraph approaches, our article on EyeDetect ocular lie detection explains how newer instruments add additional detection layers.

Legal Consequences: Federal Prosecution Cases

Attempting countermeasures during a polygraph examination carries serious consequences. If an examiner suspects countermeasure use, the test may be terminated, and the report will likely indicate that countermeasures were detected — which in many contexts is treated as equivalent to or worse than a deceptive result.

The most significant legal precedent was established through federal "Operation Lie Busters," a criminal investigation led by U.S. Customs and Border Protection targeting individuals who provided instruction on how to pass polygraph tests [14]Verified Sex Offender Polygraph Examination: An Evidence-Based Case Management Tool for Social Workers
Framed PCSOT as an evidence-based intervention improving case management and community safety monitoring for sex offender populations. Two notable prosecutions emerged from this operation:

Chad Dixon of Marion, Indiana, who operated Polygraph Consultants of America, pleaded guilty in December 2012 to wire fraud (18 U.S.C. § 1343) and obstruction of an agency proceeding (18 U.S.C. § 1505) [15]Verified Lie Detection: Its History, Methods and Techniques
Early comprehensive account of lie detection history documenting the transition from ancient ordeals to scientific instruments. He was sentenced to eight months in federal prison in September 2013, plus three years of supervised release and forfeiture of $17,000 [16]Verified Report from the National Conference on Instrumental and Non-Instrumental Methods of Detection of Deception
Conference brought together experts to discuss legal admissibility, scientific validation, and professional standards for deception detection technologies. Dixon had trained between 70 and 100 clients, charging up to $1,000 per session [17]Verified Polygraph — History and Invention
Confirms the polygraph was invented in 1921 by John Augustus Larson at the University of California, Berkeley.

Doug Williams, a former Oklahoma City police officer who ran the website Polygraph.com, was charged with two counts of mail fraud and three counts of witness tampering after undercover agents posed as clients in 2012-2013 [18]Verified A Comprehensive Meta-Analysis of the Comparison Question Polygraph Test
Meta-analysis of 138 datasets confirmed CQT accuracy is significant and that experimental studies are generalisable to field conditions. Williams pleaded guilty in May 2015 and was sentenced to two years in prison by U.S. District Judge Vicki Miles-LaGrange in September 2015.

These cases established that while discussing polygraph countermeasures in general may be protected speech, knowingly coaching individuals to deceive government agencies during official proceedings can result in federal prosecution. The charges used were wire fraud, mail fraud, obstruction, and witness tampering — not a specific anti-countermeasure statute. For more on how the government has overseen polygraph practices, see our article on the Church Committee and polygraph oversight.

Professional Consequences

Beyond criminal prosecution, the professional consequences of detected countermeasure use are severe. In law enforcement hiring contexts, a finding of countermeasure use typically results in permanent disqualification from the hiring process — not just with the agency administering the test, but potentially across agencies that share polygraph results.

For security clearance investigations, a countermeasure finding can result in denial or revocation of clearance, effectively ending careers in national security, intelligence, and defence contracting. In post-conviction sex offender testing (PCSOT), a countermeasure finding can trigger probation violations and potential re-incarceration.

For those navigating the screening process, understanding what to expect is far more productive than attempting countermeasures. Our guide on counterintelligence polygraph vs. full scope testing explains the different types of examinations and what each involves.

The Best Strategy Is Cooperation

After examining all ten myths, the conclusion is clear: the most effective strategy for a polygraph examination is honest preparation and genuine cooperation with the examiner. This means understanding the process ahead of time, disclosing all relevant information during the pre-test interview, following the examiner's instructions, and answering questions truthfully.

Polygraph testing has been in use for over a century, dating back to John Larson's invention of the first modern polygraph instrument at the Berkeley Police Department in 1921. Over more than 100 years of refinement, the technology and methodology have evolved specifically to counter every known countermeasure technique. Modern computerised scoring algorithms, motion sensors, and examiner training programs represent the accumulated knowledge of decades of countermeasure research.

A truthful person who understands the test process has nothing to fear from a properly conducted polygraph examination. General test anxiety is normal, expected, and accounted for in the test design. The comparison question technique is specifically engineered to distinguish between general nervousness and the specific physiological response associated with deception [4]Verified The Comparison Question Polygraph Test: A Contrast of Methods and Scoring
Mock crime experiment with 250 participants found substantial main effects of guilt in both computer and human scoring of CQT variants.

Before your examination, read about the test process, understand the types of questions you will be asked, and arrive well-rested and prepared to cooperate fully. Review our guide on the polygraph consent form to understand what you will be agreeing to, and familiarise yourself with the NRC 2003 report for an objective scientific perspective.