“A fallacy is an error in reasoning whereby someone attempts to put forward an argument whereby a conclusion supposedly has been appropriately inferred from a premise (or premises) when, in fact, the conclusion does not and should not be inferred from the premise(s)” as the book Bad Arguments tells me (p. 19), a book I have used already often in these blogs. Fallacies can be divided into formal and informal fallacies, so it explains. In the former type of fallacies the conclusion doesn’t follow from the premise(s) because of errors in the structure or form of the argument, rather than in the content. In an informal fallacy, the conclusion doesn’t follow from the premise(s) just because of errors in the content of the argument, rather than in its structure or form. Since the content is expressed in language, often we find the false reasoning in the language used, like the misuse of words or grammar, false understanding, vague use of conceptions, and so on. (pp. 18-22) It is not only because fallacies are based on false reasoning (which often happens in good faith), that I treat them sometimes in these blogs, but they are also often used intentionally to manipulate other people. In both cases, fallacies can lead to wrong decisions, prejudice, wrong behaviour etc. Many fallacies leading to prejudices, discrimination and other unwanted social consequences are based on a confusion between group level and individual level, so on the view that what is true for a group should also be true for members of this group, or the other way around.
One fallacy where this confusion occurs is the ecological fallacy, also called population fallacy. It is a deduction error committed when “we try to draw conclusions about individuals based on data collected at the group level.” (Source 1, or (1) for short) Or, alternatively, it is an error “in the interpretation of statistical data … when inferences about the nature of individuals are deduced from inferences about the group to which those individuals belong.” (Source 2, or (2) for short) Since the basis of this fallacy is an error in formal deduction, the ecological fallacy is a formal fallacy. This fallacy often leads to stereotyping, prejudices and discrimination, as this example illustrates: If a specific neighbourhood has a high crime rate, one might assume that any resident living in that area is more likely to commit a crime. However, it needs not to be so that if you take an arbitrary resident of this neighbourhood that he or she ever has committed a crime. Nevertheless, stereotypical thinking often assumes that groups are homogeneous and that every resident of such a neighbourhood has an air of criminality around him or her and that he or she has directly or indirectly something to do with criminality. If for someone this clearly appears not to be the case, that person is seen as atypical.
The ecological fallacy is often seen as a case of misinterpretation of statistical data and so seen as a fallacy typically committed by researchers or others who directly work with statistical data, but actually it is a fallacy that is committed more generally (cf. the example).
The ecological fallacy is a kind of “group fallacy”: Group level and individual level are confused; or otherwise; the group as a whole is incorrectly substituted as a principle of explanation of what individuals in the group do or are. The individual is completely identified with the group, ignoring individual differences. A related fallacy that confuses group and individual is the fallacy of division. It “occurs when one reasons that something that is true for a whole must also be true of all or some of its parts.” (3) The feature of a group is incorrectly also ascribed to the individuals comprising the group (6). It is an informal fallacy based on the content of the reasoning. Here is an example: A) The laws passed by the parliament were radical; B) Jones is a member of the parliament. Therefore from A and B: C) Jones is radical. (4). I think it is clear that this needs anything but true, albeit only because it might be that Jones was the only person who voted against the laws.
The opposite reasoning is also possible, so instead of reasoning from group to individual arguing from individual to group. The fallacy of composition is a case in point. This informal fallacy is the incorrect inference that if something is true for a part, it is also true for the whole (4), or “that the characteristics, attributes, or features of individuals comprising some group will also be found in the group as a whole” (5). For example, the members of parliament Peterson, Smith and Mark are all radicals, therefore the whole parliament is radical. This needs not be true, of course, since maybe the other MPs are all moderates. This fallacy is related to the fallacy of hasty generalization, which I have discussed elsewhere in these blogs.
The way to avoid these mistakes differs a bit from fallacy to fallacy but the general approach is never to suppose that what is true for a higher level is also true for the lower level, and the other way around. Maybe it is, but then this conclusion must always be based on independent data. Otherwise the road is open to stereotyping, prejudices and discrimination.
Sources
1) “What Is Ecological Fallacy? | Definition & Example”
2) Wikipedia: “Ecological fallacy”
3) Wikipedia: “Fallacy of division”
4) Wikipedia: “Fallacy of composition”
5) Jason Waller, “Composition”, in Bad Arguments, pp. 250-251
6) Jason Waller, “Division”, in Bad Arguments, pp. 259-260
