CAPTCHAs can assume cultural knowledge beyond the US
A 2017 blog post argues that prompts such as identifying yellow taxis may test familiarity with American conventions as much as whether a user is human.
A blog post published in November 2017 questioned whether CAPTCHA challenges can depend on cultural knowledge that is not shared by users around the world. Its author drew on personal experiences with both an IQ test and a Google CAPTCHA.
As a child, the author encountered an IQ test question about buying 25 cents’ worth of candy with a dime and nickels. Unfamiliar with those US coins and the cent symbol, they could not answer without knowledge the question assumed.
Years later, a CAPTCHA asked the author to identify yellow taxis. The post noted that London taxis are generally black and that taxi colours vary in other countries. It also cited Twinkies as an example of American cultural knowledge a user might not have.
The author’s argument is that such prompts may measure familiarity with particular cultural conventions alongside a person’s ability to recognise images. The post raises questions about whether CAPTCHA tests work consistently across cultural contexts.
The examples are personal observations. The post provides no data on how often culturally specific prompts appear or whether CAPTCHA systems broadly disadvantage people outside the US.
