Visitors to the Serpentine Sackler Gallery in London may think they've walked in while an exhibition is being set up. Two workmen on their lunch break are sitting around, while another is painting a wall. A cleaner stands gazing vacantly into the middle distance.

These figures are works by the late American artist Duane Hanson (1925 - 1996). Over a 40-year career, he created incredibly lifelike sculptures portraying working-class Americans and overlooked members of society.

Julia Peyton-Jones and Hans Ulrich Obrist of the Serpentine Galleries, said: "Duane Hanson's iconic sculptures of ordinary people will literally stop visitors in their tracks this summer. Beyond the stunning realism, the power of Hanson's work lies in his unwavering focus on and sympathy for the human condition."

Hanson's early works confronted the viewer with harsh truths, depicting soldiers killed in action, police brutality and homeless people. Widespread criticism of his work Abortion in 1965 led to him shifting his focus. He began creating iconographic sculptures of everyday people, with some satirical aspects, that could be conceived as representative of an entire labour force, class or even a nation.

Hanson produced sculptures that represent typical Americans, concentrating on "those that do not stand out", including Man with Hand Cart (1975), Housepainter (1984/1988) and Policeman (1992/1993), all of which are included in the Serpentine exhibition.

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A journalist views Duane Hanson's 1995 sculpture Man with Hand Cart Rob Stothard/Getty images

The hyper-realistic nature of the sculptures results directly from Hanson's artistic approach. He cast figures from live models in his studio, paying attention to every detail, from body hair to veins, hangnails and bruises. He used his own children for several works, including Children Playing Game (1979).

The sculptures were assembled, adapted and finished meticulously, with the artist hand-picking clothes and accessories from second-hand stores.

Although some critics have likened his work to figures in a wax museum, his sculptures are more subtly expressive, with real emotional content. You can judge for yourself this summer at the Serpentine Sackler Gallery in Kensington Gardens. The exhibition runs from 2 June to 13 September 2015.