Human beings have, ever since they developed distinct cultures, always worried that their purity might soon be blemished. In ancient Greece, Therpandrus caused offence by adding an extra string to his lyre. In 16th-century China, the emperor ordered all seafaring ships destroyed because of fears about the cultural changes that foreign trade missions might induce. In 19th-century Germany, the composer Richard Wagner worried that Jews might spoil the authenticity of German culture. Traditionally, it has been the right that opposed and the left that defended new cultural influences. But, in recent years, many progressives have also started to worry about ways in which cultures might cross-pollinate. While they celebrate a great variety of traditional cultures, they now warn about the dangers of “cultural appropriation”. Most recently, musicians have been shamed for copying the styles of minority groups and chefs have been boycotted for emulating the cuisines of different nations. As part of its “archive repair project”, Bon Appétit magazine apologised for allowing a gentile writer to publish a recipe for hamantaschen, a traditional Jewish dessert. In Britain, newspapers weighed in on whether Jamie Oliver could cook jollof rice and whether it was offensive for Adele to wear a traditional African hairstyle to the Notting Hill carnival in London. At the Reading festival this summer, organisers prohibited wearing non-western clothes that might “promote cultural appropriation”. In many milieus, it is now widely accepted that decent people should avoid committing anything that might in any way be seen as a form of appropriation. One reason for this is that some cases of so-called cultural appropriation do amount to real injustices. It was, for example, immoral for White musicians in the US to steal the songs of Black artists who were barred from big careers because of racial discrimination, or for collectors in the UK to loot art from the country’s former colonies. But does the concept of cultural appropriation actually help to express what is wrong in such cases? No. To see why, it helps to examine more closely some supposed cases. In Waco, Texas, in 2017, for example, members of Baylor University’s Kappa Sigma fraternity hosted a “Cinco de Drinko” party in a malicious parody of a holiday celebrating Mexican American heritage. A number of students came to the frat house sporting ponchos and sombreros. Some of the girls had dressed up as maids. Two boys dancing on a table were clad in construction workers’ outfits. What was wrong with this party, its critics argued, is that students who are not Latino appropriated elements of Mexican culture for their own purposes. But this would have a highly implausible implication. Ponchos and sombreros are part of traditional Mexican culture. Maids’ outfits and construction vests are not. So, from the perspective of cultural appropriation, the students who wore ponchos or sombreros were doing something wrong but those who wore maids’ outfits or construction vests were not. This is absurd. While wearing a poncho or a sombrero may be tacky, wearing a maid’s outfit or a construction vest to a Mexican-themed party is a far more pointed and cruel insult: the intention was clearly to imply that Latinos should be cleaners or manual labourers, not college students or professionals. A similar failure to describe the actual nature of the injustice is at play in virtually all cases in which the media invokes the spectre of cultural appropriation. Rock’n’roll artists such as Pat Boone have been blamed for stealing songs from Black musicians who were barred from fame and wealth because of the colour of their skin. It is beyond doubt that these Black musicians suffered harm – and very much in doubt that the concept of cultural appropriation best describes the nature of that harm. For justice would have consisted not in stopping Boone from popularising that music, allowing millions of people to share in its joy, but rather in overcoming the severe discrimination that stopped African American performers such as Little Richard, Big Mama Thornton and Muddy Waters from enjoying the rightful fruits of their creative efforts. The concept of cultural appropriation is incoherent, making it harder for us to recognise what philosophers call the “wrong-making features” of genuine injustices. It also creates serious harms of its own by putting healthy forms of cultural exchange under a general pall of suspicion. All of the greatest dishes, customs and inventions on which humanity can pride itself have roots in many cultures. Trying to assign particular instances of culture to one group in a clean way is a fool’s errand. If humans were to be restricted from drawing on the cultures of all groups in the future, we would, for the same reasons, fundamentally restrict our collective creativity. As the British-born Ghanaian-American philosopher Kwame Anthony Appiah has pointed out: “Trying to find some primordially authentic culture can be like peeling an onion… Cultures are made of continuities and changes, and the identity of a society can survive through these changes. Societies without change aren’t authentic; they’re just dead.” Throughout human history, different groups of people have influenced and emulated one another. So it should be little surprise that some of the most celebrated epochs of human history have come at times, and in places, that allowed cultures to inspire one another. From the Baghdad of the ninth century to the Vienna of the 19th to London and New York in the 21st, it was cultural hybridity that allowed diverse societies to thrive and shine. Some of the behaviours that supposedly fall under the rubric of appropriation really are unjust or reprehensible. But the concept fails to explain what makes them wrong, and now runs the danger of making us far too apprehensive about the beautiful and constructive ways in which we can build on each other’s cultures. Instead of condemning appropriation, we should seek to build a society in which members of every group are valued equally – and all are free to draw inspiration from the cultures of their compatriots. The joy of mutual influence is not a sin against which diverse societies should be on guard. It is the key promise they hold out to us if we get things right. Yascha Mounk is a professor of the practice of international affairs at Johns Hopkins University. His latest book is The Identity Trap: A Story of Ideas and Power in Our Time, published by Penguin on 26 September. To support the Guardian and Observer, order your copy at guardianbookshop.com. Delivery charges may apply.