{"id":1039,"date":"2024-04-14T12:46:57","date_gmt":"2024-04-14T10:46:57","guid":{"rendered":"https:\/\/guillaume-guerard.com\/?page_id=1039"},"modified":"2024-04-14T13:00:42","modified_gmt":"2024-04-14T11:00:42","slug":"sophisme-post-hoc","status":"publish","type":"page","link":"https:\/\/guillaume-guerard.com\/en\/cours-de-methodologie\/sophisme-post-hoc\/","title":{"rendered":"Post hoc ergo propter hoc fallacy"},"content":{"rendered":"<div data-elementor-type=\"wp-page\" data-elementor-id=\"1039\" class=\"elementor elementor-1039\">\n\t\t\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-ba8ff0c elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"ba8ff0c\" data-element_type=\"section\" data-e-type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-50 elementor-top-column elementor-element 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elementor-top-column elementor-element elementor-element-765fcf5\" data-id=\"765fcf5\" data-element_type=\"column\" data-e-type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-08de274 elementor-align-justify elementor-widget elementor-widget-button\" data-id=\"08de274\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"button.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<div class=\"elementor-button-wrapper\">\n\t\t\t\t\t<a class=\"elementor-button elementor-button-link elementor-size-sm\" href=\"https:\/\/complex-systems-ai.com\/\" target=\"_blank\" rel=\"noopener\">\n\t\t\t\t\t\t<span class=\"elementor-button-content-wrapper\">\n\t\t\t\t\t\t\t\t\t<span class=\"elementor-button-text\">Data Science<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-7d5b272 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"7d5b272\" data-element_type=\"section\" data-e-type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-fdbcb0c\" data-id=\"fdbcb0c\" data-element_type=\"column\" data-e-type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-7c00d54 elementor-widget elementor-widget-heading\" data-id=\"7c00d54\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_82_2 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Page contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Contents\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewbox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewbox=\"0 0 24 24\" version=\"1.2\" baseprofile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/guillaume-guerard.com\/en\/cours-de-methodologie\/sophisme-post-hoc\/#Sophisme_post_hoc\" >Post hoc fallacy<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/guillaume-guerard.com\/en\/cours-de-methodologie\/sophisme-post-hoc\/#Cause\" >Cause<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/guillaume-guerard.com\/en\/cours-de-methodologie\/sophisme-post-hoc\/#Exemple\" >Example<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/guillaume-guerard.com\/en\/cours-de-methodologie\/sophisme-post-hoc\/#Comment_eviter_une_erreur_post_hoc\" >How to avoid a post hoc error?<\/a><\/li><\/ul><\/nav><\/div>\n<h2 class=\"elementor-heading-title elementor-size-default\"><span class=\"ez-toc-section\" id=\"Sophisme_post_hoc\"><\/span>Post hoc fallacy<span class=\"ez-toc-section-end\"><\/span><\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-408c736 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"408c736\" data-element_type=\"section\" data-e-type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-908b0cb\" data-id=\"908b0cb\" data-element_type=\"column\" data-e-type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-36f5a0a elementor-widget elementor-widget-text-editor\" data-id=\"36f5a0a\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>The post hoc fallacy is the assumption that because one event preceded another event, they must be causally related. In other words, the first event must have caused the second. However, the chronological order of two events does not prove a cause and effect relationship between them.<\/p><p><img decoding=\"async\" class=\"alignnone wp-image-49 size-thumbnail\" src=\"http:\/\/guillaume-guerard.com\/wp-content\/uploads\/2023\/07\/logo_sc-150x150.png\" alt=\"sophisme post hoc\" width=\"150\" height=\"150\" srcset=\"https:\/\/guillaume-guerard.com\/wp-content\/uploads\/2023\/07\/logo_sc-150x150.png 150w, https:\/\/guillaume-guerard.com\/wp-content\/uploads\/2023\/07\/logo_sc-70x70.png 70w, https:\/\/guillaume-guerard.com\/wp-content\/uploads\/2023\/07\/logo_sc-125x125.png 125w\" sizes=\"(max-width: 150px) 100vw, 150px\" \/><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-22bdb85 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"22bdb85\" data-element_type=\"section\" data-e-type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-095c81f\" data-id=\"095c81f\" data-element_type=\"column\" data-e-type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-eb63e7b elementor-widget elementor-widget-heading\" data-id=\"eb63e7b\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\"><span class=\"ez-toc-section\" id=\"Cause\"><\/span>Cause<span class=\"ez-toc-section-end\"><\/span><\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-3cc79a9 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"3cc79a9\" data-element_type=\"section\" data-e-type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-873dfe4\" data-id=\"873dfe4\" data-element_type=\"column\" data-e-type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-23192fe elementor-widget elementor-widget-text-editor\" data-id=\"23192fe\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>The post hoc error occurs when we draw a <a href=\"https:\/\/guillaume-guerard.com\/en\/cours-de-methodologie\/parfaire-la-conclusion\/\">conclusion<\/a> causal without sufficient evidence to support it. \u201cPost hoc\u201d is a shortened version of the Latin phrase \u201cpost hoc ergo propter hoc,\u201d meaning \u201cafter this, therefore because of that.\u201d Post hoc errors are made when one argues that because B occurred immediately after A, A must be the cause of B. The problem is not that there cannot be a causal connection between A and B, but rather that there is no adequate evidence. for the conclusion.<\/p><p>The post hoc fallacy leads to misconceptions about the causes of various phenomena. It is at the heart of many pseudoscientific arguments, the most notable and persistent being the false belief that certain types of vaccines cause autism in children.<\/p><p>The post hoc fallacy can also lead to magical thinking: the belief that unrelated events are causally related despite the absence of any plausible connection (e.g., believing that inner thoughts can influence the external world without action). Superstitions (for example, attributing misfortune to an \u201cunlucky\u201d event such as walking under a ladder) follow the same pattern.<\/p><p>Sometimes people make a logical leap into hindsight when they believe they can eliminate a problem by eliminating its (alleged) cause.<\/p><p>This is often reflected in how politicians interpret unemployment statistics or crime reduction. In this case, the post hoc fallacy (A caused B) is combined with antecedent negation, another fallacy that goes even further by assuming that &quot;if A caused B, avoiding A will prevent B.&quot;<\/p><p>People often make the post hoc fallacy without realizing it, simply because of the way the human mind evolved: it extracts causality from coincidences. For this reason, people confuse the temporal order of events with a true causal connection. Chronological order is a necessary but not sufficient condition for a cause and effect relationship.<\/p><p>A number of cognitive biases can also fuel people&#039;s tendency to get caught in the hindsight fallacy trap. For example, jumping to conclusions bias (making decisions without enough information) can cause people to infer causality.<\/p><p>Likewise, confirmation bias can cause people to seek out or interpret information in a way that confirms their pre-existing belief that a cause-and-effect relationship exists.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-d921d56 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"d921d56\" data-element_type=\"section\" data-e-type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-c21ac6c\" data-id=\"c21ac6c\" data-element_type=\"column\" data-e-type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-6058cf5 elementor-widget elementor-widget-heading\" data-id=\"6058cf5\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\"><span class=\"ez-toc-section\" id=\"Exemple\"><\/span>Example<span class=\"ez-toc-section-end\"><\/span><\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-cd6a591 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"cd6a591\" data-element_type=\"section\" data-e-type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-8b0a2ec\" data-id=\"8b0a2ec\" data-element_type=\"column\" data-e-type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-eedf8d7 elementor-widget elementor-widget-text-editor\" data-id=\"eedf8d7\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>In <a href=\"https:\/\/guillaume-guerard.com\/en\/cours-de-methodologie\/\">research<\/a>, post hoc error occurs when researchers do not carefully examine the relationship between variables.<\/p><p>Researchers sought to determine whether taking baths could reduce the risk of cardiovascular disease. Their analysis shows that people who took baths regularly were less likely to suffer from cardiovascular disease or stroke. Researchers conclude that baths have a beneficial effect on cardiovascular health.<\/p><p>The media picks up <a href=\"https:\/\/guillaume-guerard.com\/en\/cours-de-methodologie\/parfaire-la-section-resultats\/\">results<\/a> research and disseminate them widely with titles like \u201cTaking a bath is good for the heart\u201d.<\/p><p>However, without a controlled experiment in which participants are randomly assigned to a control group or a treatment group, it is difficult to know whether this relationship is causal. For example, an alternative explanation could be that those who bathe regularly have more time and are generally less stressed.<\/p><p>Claiming that bathing is the cause of lower rates of heart disease among people who bathe regularly is a form of post hoc fallacy.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-85a9eb4 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"85a9eb4\" data-element_type=\"section\" data-e-type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-3e52e2e\" data-id=\"3e52e2e\" data-element_type=\"column\" data-e-type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-43a93f7 elementor-widget elementor-widget-heading\" data-id=\"43a93f7\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\"><span class=\"ez-toc-section\" id=\"Comment_eviter_une_erreur_post_hoc\"><\/span>How to avoid a post hoc error?<span class=\"ez-toc-section-end\"><\/span><\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-ddbd07a elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"ddbd07a\" data-element_type=\"section\" data-e-type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-dbb18e9\" data-id=\"dbb18e9\" data-element_type=\"column\" data-e-type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-7140766 elementor-widget elementor-widget-text-editor\" data-id=\"7140766\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>Correlation does not imply causation (the converse can also be true). Be careful to always talk about correlation or hypothesis and not to put everything under the term causality.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<\/div>","protected":false},"excerpt":{"rendered":"<p>Home Data Science Post hoc fallacy Post hoc fallacy is the assumption that because an event preceded a... <\/p>","protected":false},"author":1,"featured_media":0,"parent":47,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"elementor_header_footer","meta":{"footnotes":""},"class_list":["post-1039","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/guillaume-guerard.com\/en\/wp-json\/wp\/v2\/pages\/1039","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/guillaume-guerard.com\/en\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/guillaume-guerard.com\/en\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/guillaume-guerard.com\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/guillaume-guerard.com\/en\/wp-json\/wp\/v2\/comments?post=1039"}],"version-history":[{"count":4,"href":"https:\/\/guillaume-guerard.com\/en\/wp-json\/wp\/v2\/pages\/1039\/revisions"}],"predecessor-version":[{"id":1047,"href":"https:\/\/guillaume-guerard.com\/en\/wp-json\/wp\/v2\/pages\/1039\/revisions\/1047"}],"up":[{"embeddable":true,"href":"https:\/\/guillaume-guerard.com\/en\/wp-json\/wp\/v2\/pages\/47"}],"wp:attachment":[{"href":"https:\/\/guillaume-guerard.com\/en\/wp-json\/wp\/v2\/media?parent=1039"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}