Body & HealthFact
The tongue map from school is a misreading.
Sweet at the tip, bitter at the back, sour at the sides: this map goes back to a 1901 paper that found only tiny differences in sensitivity. An American psychologist summarised it in 1942 in a way that created exclusive zones. In reality, taste buds all over the tongue detect all five qualities. Test it with sugar at the tip and back.
Useful: A myth that survived over 50 years in textbooks because hardly anyone checked.
Source: en.wikipedia.org