LET'S talk about sex. Bill Condon's fascinating biopic turns the microscope on pioneering scientist Alfred Kinsey (Liam Neeson), who caused a sensation in January 1948 with the publication of his medical journal Sexual Behaviour In The Human Male.

Based on thousands of sex histories of American men taken by Kinsey and his researchers Clyde Martin (Peter Sarsgaard), Wardell Pomeroy (Chris O'Donnell) and Paul Gebhard (Timothy Hutton), the book shattered taboos about sex behind the white picket fences of American society.

Between 67 per cent and 98 percent of men confessed to having sex before marriage depending on their social class, while 37 per cent of American men related at least one homosexual experience.

Overnight, Kinsey became a media darling and the book's original print run of 25,000 sold out in days. Behind the scenes, Kinsey practised very much what his book preached - frankness and honesty between couples - enjoying an open marriage with his adoring wife Clara (Laura Linney).

They shared lovers, including Clyde who perhaps foresaw trouble when he observed, "Sex is a risky game because if you're not careful, it will cut you wide open."

Kinsey's private sexual utopia of partner-swapping and experimentation gradually sowed seeds of jealousy and mistrust between the research team members.

Five years later, when he published the companion volume Sexual Behaviour In The Human Female, America turned on Kinsey, unable to stomach the same frankness about its mothers and daughters.

Kinsey went from hero to cultural pariah. A few years later, he died of a heart attack.

Shot in the style of one of Kinsey's probing sex study interviews, Condon's film is a revealing portrait of a complex, driven yet emotionally damaged man, whose work lit the touch-paper on the sexual revolution of the 60s.

The film brings into focus Kinsey's fraught relationship with his overbearing father (John Lithgow), a stern Methodist and Sunday school teacher who sermonised the downfall of a sexualised human society.

Neeson beautifully conveys the passion and social ineptitude of the great man and Linney delivers another intense performance as his long-suffering wife.

She also delivers the film's best line, answering her husband's suggestion that she sleep with Clyde with a perky "I think I might like that!" There's a welcome dusting of humour, like Wardell mishearing one research subject's response "whores" as "horses".

Learning has rarely been so enjoyable.

Rating 8/10