| Confirmation Bias |
Leads to favoring information that confirms preexisting beliefs, disregarding contradictory evidence. |
A physician might continue to suspect a particular disease because of initial test results and personal bias, ignoring subsequent test results that suggest a different diagnosis. |
| Post Hoc Ergo Propter Hoc |
Causes erroneous attribution of causality based on sequence rather than evidence. |
Assuming a patient's symptoms improved because of a specific medication, without considering other factors or interventions that occurred simultaneously. |
| Anchoring Bias |
Results in over-reliance on initial information, potentially overlooking subsequent evidence. |
If a patient presents symptoms that initially suggest a common illness, the doctor might focus on that diagnosis even when further symptoms or test results suggest a different condition. |
| Availability Heuristic |
Overestimates the likelihood of diagnoses or outcomes based on recency or memorability. |
After diagnosing several cases of a rare disease, a physician may overestimate its prevalence and incorrectly diagnose subsequent patients with the same condition. |
| False Dilemma/False Dichotomy |
Limits consideration to two options when more are available, potentially overlooking valid diagnoses or treatments. |
Concluding that a patient either has a psychological disorder or is faking their symptoms, without considering organic causes of their symptoms. |
| Overgeneralization |
Leads to broad conclusions from narrow evidence, risking inappropriate treatment choices. |
Believing a treatment is ineffective because it did not work in a few cases, without considering individual patient differences or the possibility of incorrect application. |
| Appeal to Authority |
May discourage critical analysis in favor of authoritative opinions. |
A junior doctor not questioning a senior doctor’s diagnosis, despite having evidence or a hunch that suggests another diagnosis might be more accurate. |
| Bandwagon Fallacy |
Encourages adoption of diagnoses, treatments, or trends without sufficient evidence. |
Prescribing a medication because it has become a popular choice among peers. |
| Wishful Thinking |
Allowing hopes or desires to influence diagnostic or treatment decisions. |
Hoping for a more favorable diagnosis for a patient and therefore ignoring or downplaying evidence that points to a more serious condition. |
| Hasty Generalization |
Drawing conclusions from insufficient evidence. |
Concluding that a treatment is highly effective based on a few positive outcomes, without considering larger, more comprehensive studies or data. |
| Slippery Slope |
Leads to avoidance of beneficial treatments due to unfounded fear of negative outcomes. |
Believing that prescribing a mildly addictive painkiller will definitely lead to addiction and therefore avoiding its use even when it's indicated. |
| False Cause |
Attributing causation without evidence supporting the causal connection. |
Assuming that because a patient's symptoms worsened after starting a new diet, the diet must be the cause of the worsening, without considering other variables like disease progression or other lifestyle changes. |
| Circular Reasoning (Begging the Question) |
Using the conclusion as a premise of the argument, leading to circular justification. |
Claiming a treatment works because it is effective, without providing independent evidence of its effectiveness. |
| Straw Man |
Misrepresenting an argument to make it easier to attack or refute. |
A physician might oversimplify a colleague’s cautious approach to treatment as being completely against medication, thus ignoring the nuances of the colleague’s actual position. |
| Appeal to Ignorance (Argumentum ad Ignorantiam) |
Assuming something is true because it has not been proven false, and vice versa. |
Claiming a new treatment is safe because there have been no reports of harm, without sufficient studies or evidence to actually prove its safety. |
| Sunk Cost Fallacy |
Continuing a chosen course of action because of previous investments despite new evidence suggesting a change. |
Persisting with a costly treatment regimen that is not showing benefits because of the investment already made in terms of time, effort, and expense. |
| Appeal to Tradition |
Valuing methods or treatments simply because they have been used in the past. |
Continuing to use a medical procedure because "it's always been done that way," ignoring new evidence or technologies that suggest better alternatives. |
| Appeal to Novelty |
Favoring treatments or diagnostics because they are new, equating novelty with superiority. |
Favoring the latest medical device or drug without thoroughly evaluating its effectiveness compared to existing treatments. |
| Cherry Picking (Selective Evidence) |
Selecting evidence that supports one's argument while ignoring contradictory evidence. |
Emphasizing studies that show positive outcomes of a treatment while disregarding studies that show no effect or negative outcomes. |
| Equivocation |
Using ambiguous terms to mislead or justify a misleading conclusion. |
Using the term "recovery" to mean both symptom improvement and complete disease eradication interchangeably, leading to confusion about the effectiveness of a treatment. |
| Burden of Proof |
Demands that the opponent prove a claim is false rather than providing evidence to prove it is true. |
Insisting that others prove a novel treatment is ineffective rather than providing robust evidence of its efficacy. |
| False Equivalence |
Assuming two things are the same because they share some characteristics, ignoring significant differences. |
Equating the effectiveness of two different drugs because they're both classified as painkillers, ignoring differences in their action mechanisms, side effects, and efficacy. |
| Slippery Slope |
Assuming a first step will inevitably lead to a negative series of events without causal connection. |
Believing that prescribing a mild sedative for anxiety will inevitably lead to dependency, abuse, and serious drug addiction without considering controlled usage and monitoring practices. |
| Composition/Division Fallacy |
Assuming what's true for the part is true for the whole, or vice versa. |
Assuming that because a medication has side effects in elderly patients, it is unsafe for all age groups. Assuming a treatment effective for a population will be equally effective for every individual within that population. |
| No True Scotsman |
Making an appeal to purity as a way to dismiss relevant criticisms or flaws of an argument. |
Dismissing evidence of a treatment's ineffectiveness by claiming that it wasn't administered "correctly," without specifying what the correct administration entails. |
| Ad Hominem |
Attacking the person making an argument rather than the argument itself. |
Discrediting a colleague's diagnosis by questioning their credentials or experience rather than addressing the reasoning or evidence behind their diagnosis. |
| Tu Quoque (Appeal to Hypocrisy) |
Dismissing someone's argument because they are inconsistent in practice. |
Ignoring advice from a healthcare professional about healthy lifestyle choices because they don't always follow those choices themselves. |
| Moving the Goalposts |
Arbitrarily changing the criteria of a claim when it has been met. |
After a treatment meets the initially agreed-upon success criteria, demanding additional evidence or outcomes for it to be considered effective. |
| Ambiguity |
Using a word or expression in an unclear or vague way to mislead or justify a misleading conclusion. |
Using the term "natural" in a way that implies safety and effectiveness without substantiating these qualities. |
| The Gambler’s Fallacy |
Believing that past events can affect the likelihood of something happening in the future, under circumstances where the events are independent. |
After a series of patients experience adverse effects from a medication, believing the next patient is less likely to experience them, as if there's a balancing force at play. |
| Appeal to Emotion |
Attempting to manipulate an emotional response in place of a valid or compelling argument. |
Suggesting a particular treatment by emphasizing heartwarming recovery stories rather than presenting data on its efficacy and safety. |
| Red Herring |
Introducing an irrelevant topic to divert attention from the subject at hand. |
When questioned about the efficacy of a certain treatment, a healthcare provider brings up the cost of alternative treatments, diverting from the original question of efficacy. |
| Appeal to Fear |
Using fear to persuade others to accept a conclusion. |
Suggesting a specific diagnostic test by overly emphasizing the possibility of a rare but serious condition, instilling unnecessary fear to sway the patient's decision. |
| False Balance |
Presenting two sides of an issue as if they are equally supported by evidence, despite one side being significantly less credible. |
Giving equal weight to the opinions of a vastly experienced specialist and a source with dubious credentials when discussing treatment options. |
| Moral Equivalence |
Comparing minor misdeeds with major atrocities, suggesting that both are equally immoral. |
Equating the minor side effects of a vaccine with severe consequences of preventable diseases to argue against vaccination. |
| Non Sequitur |
Presenting an argument whose conclusions do not logically follow from its premises. |
Claiming a patient must not be suffering from a particular condition because they do not fit the stereotype associated with that condition. |
| The Texas Sharpshooter Fallacy |
Ignoring the differences while focusing on the similarities, making a random occurrence seem like a meaningful pattern. |
Noticing a series of successful outcomes for a particular treatment in a small group and concluding the treatment is highly effective, without acknowledging broader and more varied data that doesn't support this conclusion. |
| Middle Ground (False Compromise) |
Assuming that the compromise between two positions is always the truth. |
Believing that the best treatment plan must lie exactly between what two conflicting studies recommend, without evaluating the validity or relevance of each study's findings. |
| Hedging |
Using ambiguous language to evade a direct statement or to blur the truth. |
Giving a vague or non-committal answer when asked about the potential side effects of a treatment, thereby not providing clear information. |
| Faulty Analogy |
Assuming that because two things are alike in one or more respects, they are necessarily alike in some other respect. |
Comparing the human body to a machine in an oversimplified manner to justify a particular treatment approach, ignoring the complex biological differences. |
| Argument from Silence (Argumentum ex Silentio) |
Assuming that because there is no evidence presented against a position, that position is correct, or vice versa. |
Assuming a medication is safe because there have not been any published reports of its dangers, disregarding the lack of comprehensive research. |
| Appeal to Pity (Ad Misericordiam) |
Attempting to induce pity to sway opponents. |
Suggesting a patient's story is so heartbreaking that they must be given a particular drug, even if it's not the most appropriate treatment for their condition. |
| Argument from Incredulity |
Assuming that because something is hard to believe, it must not be true, or conversely, if it seems too obvious, it must be true. |
Dismissing a rare diagnosis because it seems too improbable, despite evidence pointing in that direction. |
| The Fallacy of Exclusion |
Ignoring significant information that does not support one's conclusion or argument. |
Excluding evidence from a patient's history that contradicts a preferred diagnosis, thus narrowing the diagnostic focus inappropriately. |
| Argumentum ad Populum (Bandwagon Appeal) |
Assuming a claim is true because many people believe it to be true. |
Adopting a new medical procedure because it has become popular among healthcare professionals, without critically assessing its efficacy and safety based on solid evidence. |
| Naturalistic Fallacy |
Concluding about how things ought to be based on how things are or appear to be in nature. |
Asserting that natural remedies are inherently better or safer than synthetic medications without considering efficacy or potential risks. |
| The Spotlight Fallacy |
Assuming that the cases that receive the most attention are the most representative of an issue. |
Believing a particular medical condition is more prevalent than it actually is because it has been recently highlighted in the media. |
| Argument from Repetition (Ad Nauseam) |
Believing that a statement is more likely to be true the more often it is heard. |
Accepting a medical myth as truth because it has been repeatedly encountered in discussions, without seeking evidence-based verification. |
| Fallacy of Relative Privation |
Arguing that a problem is not significant because there are more serious problems in existence. |
Minimizing the importance of addressing mild symptoms in a patient by comparing them to more severe health issues. |
| Appeal to Worse Problems (Fallacy of the Worse Problem) |
Dismissing an issue or problem by pointing out something that is perceived to be a worse issue. |
Ignoring patient complaints about side effects of a medication by focusing on the severity of the disease it treats, suggesting the side effects should not be a concern. |
| Fallacy of Composition |
Assuming what's true for the individual must be true for the group, or what's true in some cases must be true in all. |
Assuming a treatment that works well for one patient will work equally well for all patients with the same condition. |
| Fallacy of Division |
Believing that what is true for the group must be true for individuals within the group. |
Believing that if a study finds a treatment effective on average, it must be effective for every individual patient. |
| Single Cause Fallacy |
Assuming there is a single, simple cause of an outcome when in reality it may have been caused by a complex interaction of factors. |
Attributing a patient's obesity solely to overeating and ignoring other potential factors like genetics, metabolism, and psychological conditions. |
| The Fallacy of the Single Cause (Causal Oversimplification) |
Assuming a complex issue has a single cause. |
Assuming patient non-compliance is the only reason for treatment failure, overlooking factors like adverse effects, misunderstanding instructions, or financial constraints. |
