Hand-painted Zulu warriors with cartoonish, red lips and grinning tribes people: these are among the images used on posters to attract members of the public to “human zoo” exhibits held just a handful of decades ago.

The startling images of people of colour put on display for entertainment are part of the Human Zoos: Putting People on Display exhibition currently running in Liverpool.

Human zoos were most popular during the late 19th and early 20th centuries. While they were foremost forms of entertainment, such events were based on false and racist "science", and helped to justify colonialism and hierarchies among ethnic groups, explains Charles Forsdick, Professor of French and leadership fellow of Translating Cultures at the University of Liverpool.

Human zoos - in pictures Show all 6 1 /6 Human zoos - in pictures Human zoos - in pictures Folies-Bergère. The Zulus a poster from 1878 for The Folies-Bergère a temple for "ethnic shows". In 1884, a group of Australian Aboriginals was exhibited in public theatres and scientific laboratories across the US and in Europe. A year later, only three were still alive when they arrived at the Folies-Bergère in France. At the turn of the century major European cities were showing such programming. Human zoos - in pictures "Exposition coloniale" in Stuttgart, Germany, 1928. Human zoos - in pictures The Human Races, 24 color plates by Victor Huen, 1921. Human zoos - in pictures Calina people on show at the Jardin d’Acclimatation in Paris, France. Photo taken 1892. Human zoos - in pictures Exposition Universelle de 1889: a world fair held in Paris. Human zoos - in pictures Javanese women at Exposition Universelle de 1889: the world fair held in Paris.

The phenomenon can also be traced back to victory parades in the ancient world when conquered peoples would be displayed in a show of pride by the winning side, argues Professor Forsdick. Their modern roots lie in the Renaissance period, when the first sustained and significant contact was made between European and non-European cultures.

Scroll through the gallery below to see shocking materials from the exhibition

“As such, they belong to a tradition of human curiosity about people different from ourselves, an impulse that racism replaces with various forms of fear and hatred," suggests Professor Forsdick.

The display in London and Paris of Saartjie Baartman, pejoratively known as the ‘Hottentot Venus', and Hamburg zoo owner Carl Hagenbeck's travelling human shows are among the most famous examples.

As cinemas and anti-colonial sentiment grew during the period between the First and Second World Wars, the popularity of human zoos waned. Yet, they continued to be featured in expositions and world’s fairs until the late 1950s.

More recently, the Bamboula Village in 1994 - where a biscuit company worked with a wildlife park near the French city of Nantes to recreate an ‘authentic African village’ - the ‘African village’ at Augsburg Zoo in Germany in 2005, and the Baka Pygmies exhibited in the Rainforest natural park in Yvoir, Belgium, in 2002, are arguably throwbacks to human zoos, suggests Professor Forsdick.

Now, in a tense global political climate, the photographs and posters of the shows reveal how easily racism can be normalised in popular culture, he adds.

"They show how certain human groups can treat other groups as somehow less human than themselves," he adds: "You are not born a racist, you become one."