…divorced by first light?

With its third UK series just broadcast, the premise of Channel 4's Married at First Sight is that science can successfully pair people in marriage. The hook is that selected participants agree to marry science's match 'blind' – meeting for the first time at the altar.

The science underpinning the matching, which featured quite prominently in Series 1, is shadowy in Series 3. The buoyant talk of personality types, oxytocin, attachment theory, DNA and Jason's symmetrical face (apparently, indicating that he has 'strong genes') is gone. Also gone, and perhaps just as well, is Series 1's rather snooty condescension towards online dating agencies.

Three couples are selected for marriage, all good-looking, white and articulate, representing the best matches from two thousand potential pairings. With science using only its choicest 0.15 per cent, the scorned online rivals might justifiably complain. The worst marriage agency in the world can do better than 0.15 per cent.

The weddings take place (minus one couple that has withdrawn) and the newlyweds throw themselves into married life. They desperately want marriage to work; Channel 4's producers desperately want them to have sex and admit it on camera. But instead, the newlyweds are discovering 'lack of chemistry' and things they don't like. Weren't these the incompatibilities that science was supposed to eliminate?
The scientists' answer is shifty. Science only provides the basis for a perfect relationship. If participants do not take advantage of this perfect match, granted to them by Science Itself… well, that's their fault.

By the end of Series 3, science has married off eight of its 'perfect' UK matches – but without any obvious successes. How could this be? Did the perfectly matched couples not try hard enough?

This explanation seems very unlikely, unless the broadcast footage is misleading. A much simpler alternative is that science's measures of personality types and genetic predispositions, although presented with much fanfare, are incapable of producing the sophisticated data that scientists need to judge marital compatibility. Big-noting about DNA samples and 'oxytocin hits' sounds impressive but just makes science look ridiculous when Richard, with his pet dog, ends up marrying Harriet, who can't bear dogs.

As entertainment, Married at First Sight is fun. As science, its greatest contribution is in demonstrating, albeit unintentionally, the immense difficulties that behavioural scientists face when they try to predict any specific behaviour or feelings in specific individuals in specific situations.

- Reviewed by Dr Chris Timms, who is an independent writer