{"id":72463,"date":"2025-09-19T00:50:09","date_gmt":"2025-09-19T00:50:09","guid":{"rendered":"https:\/\/www.europesays.com\/ie\/72463\/"},"modified":"2025-09-19T00:50:09","modified_gmt":"2025-09-19T00:50:09","slug":"chimpanzees-drink-the-equivalent-of-two-or-three-beers-a-day-study-says-science","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/ie\/72463\/","title":{"rendered":"Chimpanzees drink the equivalent of two or three beers a day, study says | Science"},"content":{"rendered":"<p class=\"\">The human attraction to alcoholic beverages could be, to a large extent, inherited from our primate ancestors. And in a way, it\u2019s something we share with our closest living relatives: according to a new study published this Wednesday in the scientific journal <a href=\"https:\/\/www.science.org\/doi\/10.1126\/sciadv.adw1665\" target=\"_blank\" rel=\"nofollow noopener\" title=\"https:\/\/www.science.org\/doi\/10.1126\/sciadv.adw1665\">Science Advances<\/a>, chimpanzees consume <a href=\"https:\/\/english.elpais.com\/opinion\/2023-07-30\/alcohol-in-the-city-its-everywhere-all-the-time.html\" target=\"_self\" rel=\"nofollow noopener\" title=\"https:\/\/english.elpais.com\/opinion\/2023-07-30\/alcohol-in-the-city-its-everywhere-all-the-time.html\">high doses of alcohol daily<\/a> for their body weight, through the fruit that is part of their regular diet.<\/p>\n<p class=\"\">A team of biologists from the University of California, Berkeley analyzed more than 500 fruit samples from 20 plant species in the forests of two national parks: Kibale (Uganda) and Ta\u00ef (Ivory Coast). There, chimpanzees of two different subspecies\u2014the eastern (Pan troglodytes schweinfurthii) and the western (P. t. verus)\u2014eat about 4.5 kilograms of fruit per day, with an average ethanol content of 0.31% to 0.32%. The result: an intake of between 13 and 15 grams of alcohol per day, which for both male and female chimpanzees is comparable to two or three beers for a human.<\/p>\n<p class=\"\">The researchers argue that these data support the \u201cdrunken monkey hypothesis,\u201d proposed more than two decades ago by Robert Dudley, co-author of this new research, according to which the <a href=\"https:\/\/english.elpais.com\/health\/2024-09-23\/lessons-from-ireland-the-first-country-to-put-health-warnings-on-alcohol-many-people-drink-without-being-aware-of-the-risk.html\" target=\"_self\" rel=\"nofollow noopener\" title=\"https:\/\/english.elpais.com\/health\/2024-09-23\/lessons-from-ireland-the-first-country-to-put-health-warnings-on-alcohol-many-people-drink-without-being-aware-of-the-risk.html\">human fascination with alcohol<\/a> has an evolutionary origin. The natural fermentation of ripe fruit, the theory goes, exposed hominids to small doses of ethanol for millions of years. This exposure may have led to physiological adaptations, such as more efficient enzymes for metabolizing it, but also a behavioral bias.<\/p>\n<p class=\"\">The study suggests that this common component of primates\u2019 diets may function as an olfactory cue, associating the smell of alcohol with energy-dense foods. It may also act as a feeding stimulant. According to the researchers, the psychoactive effect of alcohol could lead them to eat more food when they consume it.<\/p>\n<p class=\"\">Robert Dudley emphasizes that 85% of what chimpanzees eat is ripe fruit, a diet that naturally exposes them to the alcohol generated by fermentation: \u201cAt first, we thought there would be some ethanol in everything they ate, but we didn\u2019t know how much. Our hypothesis was that, even though each fruit had a small amount, they ate so much fruit that they would actually consume a lot of alcohol during the day.\u201d The beginnings of the drunken monkey theory date back to 2000: \u201cI had predicted it many years ago, but it took me a long time to go to Africa and do all these studies,\u201d Dudley now says.<\/p>\n<p class=\"\">This professor of integrative biology at Berkeley explains that the recently published research is the result of a five-year project in the African rainforest, characterized by a climate warm and humid enough to support fruit year-round. But the team also found clues in species that inhabit Latin America: \u201cWe\u2019ve conducted these types of measurements in Panama on spider monkey consumption. We know this is also a very likely outcome <a href=\"https:\/\/english.elpais.com\/science-tech\/2025-07-08\/the-myth-of-alpha-male-dominance-study-debunks-the-idea-that-males-always-rule-primate-societies.html\" target=\"_self\" rel=\"nofollow noopener\" title=\"https:\/\/english.elpais.com\/science-tech\/2025-07-08\/the-myth-of-alpha-male-dominance-study-debunks-the-idea-that-males-always-rule-primate-societies.html\">for primates<\/a> on the American continent,\u201d Dudley notes.<\/p>\n<p><img decoding=\"auto\" class=\"_re lazyload a_m-h\" height=\"208\"  width=\"414\"  src=\"https:\/\/www.europesays.com\/ie\/wp-content\/uploads\/2025\/09\/FFU2U62LWNCATC3CHTOJU6VGJE.png\" loading=\"lazy\"\/>Researchers analyzed more than 500 fruit samples from 20 plant species in the rainforests of Uganda and the Ivory Coast.Aleksey MaroDo chimpanzees get drunk?<\/p>\n<p class=\"\">The first archaeological evidence of human-controlled fermentation dates back 9,000 and 13,000 years, in China and the Middle East, respectively. According to the primatologist Fernando Colmenares, the relevance of the research lies in its connection with a behavior that persists in our species. \u201cAs indicated in the article, chimpanzees are <a href=\"https:\/\/english.elpais.com\/science-tech\/2024-12-30\/the-chimps-that-never-forget-it-is-impressive-that-they-remember-where-the-ants-are.html\" target=\"_self\" rel=\"nofollow noopener\" title=\"https:\/\/english.elpais.com\/science-tech\/2024-12-30\/the-chimps-that-never-forget-it-is-impressive-that-they-remember-where-the-ants-are.html\">our closest living relatives<\/a>, and I find this work interesting for reflecting on the precursors of what we see in humans today,\u201d notes the researcher.<\/p>\n<p class=\"\">Specialists insist on the importance of linking the dose to its physiological and <a href=\"https:\/\/english.elpais.com\/science-tech\/2024-06-21\/chimpanzees-take-their-own-antibiotics.html\" target=\"_self\" rel=\"nofollow noopener\" title=\"https:\/\/english.elpais.com\/science-tech\/2024-06-21\/chimpanzees-take-their-own-antibiotics.html\">behavioral effects<\/a>. While chimpanzees\u2019 ethanol consumption thresholds have been identified, insufficient detail has been given on how these factors translate into their behavior: \u201cIt is not yet known whether the amount of alcohol could cause them to behave in a particular way, similar to the behavior of a human when drinking,\u201d notes Colmenares, one of the founders of the Spanish Primatological Association.<\/p>\n<p class=\"\">According to Dudley, the lack of any obvious change in chimpanzees\u2019 behavior is due to a simple fact: they always consume alcohol with fruit. \u201cThey eat and drink at the same time, but in low concentrations. Then their stomachs fill up before they can reach the level that would make a human drunk or appear drunk.\u201d<\/p>\n<p class=\"\">It remains to be seen whether chimpanzees consciously select fruits with higher alcohol content or prefer those with lower fermentation rates. However, for Dudley, the underlying conclusion is unequivocal: \u201cAlcohol is part of our inherited diet, and we are attracted to it because it provides an energetic advantage. It\u2019s simply a natural response.\u201d<\/p>\n<p class=\"\">Sign up for <a href=\"https:\/\/plus.elpais.com\/newsletters\/lnp\/1\/333\/?lang=en\" rel=\"nofollow noopener\" title=\"https:\/\/plus.elpais.com\/newsletters\/lnp\/1\/333\/?lang=en\" target=\"_blank\">our weekly newsletter<\/a> to get more English-language news coverage from EL PA\u00cdS USA Edition<\/p>\n","protected":false},"excerpt":{"rendered":"The human attraction to alcoholic beverages could be, to a large extent, inherited from our primate ancestors. And&hellip;\n","protected":false},"author":2,"featured_media":72464,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[273],"tags":[4204,7605,18,19,17,25046,133,49695,461],"class_list":{"0":"post-72463","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-wildlife","8":"tag-africa","9":"tag-america","10":"tag-eire","11":"tag-ie","12":"tag-ireland","13":"tag-primates","14":"tag-science","15":"tag-uganda","16":"tag-wildlife"},"share_on_mastodon":{"url":"","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts\/72463","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/comments?post=72463"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts\/72463\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/media\/72464"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/media?parent=72463"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/categories?post=72463"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/tags?post=72463"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}