Natasha Kaplinsky was not the most obvious subject for Who Do You Think You Are? (BBC One). The BBC celebrity-traces-their-roots series usually relies on warm, cuddly types. And there is something unwarm – despite her beautifully coiffed hair and telegenic looks – about Kaplinsky. What would she reveal of herself in this investigation of her family tree? Cleverly, not much, but enough to hint that she was more than a crisp, autocue-reciting automaton.

We started with her father, who she ambled daughterishly alongside on a country walk. An economics professor, Raphie had been a student in South Africa in the late 1960s and had organised a sit-in at his university when the institution rescinded its offer of a job to a black lecturer. She looked at old newspaper cuttings of the event, and of her father as a ruffly-haired radical, and felt proud. She imagined his mixed feelings as he boarded a ship to the UK – he couldn’t stay in South Africa with his radical background; Kaplinsky herself had once come across a death threat he had been sent.

Kaplinsky established that her father’s side of the family had come from Poland and was ashamed to discover that they hadn’t supported Raphie in his rabble-rousing: victims of persecution themselves, they were glad that they weren’t victims in South Africa. They were the right colour.

Her mother’s side of the family were grander, and while it turned out a giant silver dish lid wasn’t, as family legend had it, a gift from King George III to her great-great-great-great-great grandfather, he did turn out to have been the King’s apothecary.

Kaplinsky skipped between these opening revelations gamely. It was patently stupid to pretend, as the programme did, that she pitched up at the Society of Apothecaries and the University of Cape Town and had the information immediately to hand. Clearly a lot of research had been done for her (and there was even one poor chap charged with getting the silver thing back to London) but Kaplinsky was sunny and engaging enough.

You could tell she was quite big on pedigree – the royal connection delighted her – and also power and influence. She wore crisp pink shirts (in high definition luridly matching her lipstick) and her hair was never less than perfect. Shock family secrets or not, Kaplinsky wasn’t going to look scruffy.

The emotional heart of the journey came when she went to Belarus. She said she feared what she would find there, as it was fairly clear that something terrible had happened to members of her father’s family. She was joined by Benny, the son of her great uncle Isaac. The story was grim: her great grandfather committed suicide after his young daughter’s death and then his wife and a second child died in a Nazi massacre. Tamara, the local historian, told Kaplinsky that the Nazis killed children with their own hands, not bullets.

Off camera we heard Kaplinsky’s gulping sobs. Isaac and his wife were sent to another Jewish ghetto. In a testimony he gave to the 1965 War Crimes Tribunal he told how he and a huge group of Jews were herded by the Nazis out of town one day. One group, including Jewish doctors, was asked to turn left, the others to carry on. Isaac was a doctor but nobody would believe him at first. Finally they did and he was allowed to join the other doctors. Then he started hearing the guns. The group he had been with were being massacred.

Kaplinsky visited a memorial to the 2,524 who died that day. Then she learnt Isaac had survived, with other Jewish resistance fighters, living underground, emerging – alive – at the war’s end. “Thank God there has been some happiness to this journey, otherwise I’d be going back in despair,” she said.

She was teary again at home but said proudly that her family was about “survival, hope and contribution”. It was strange but even with this wealth of very emotional family history, it was hard to feel for Kaplinsky. Maybe its her briskness and efficient, almost blank expression of neutrality when things upset her that forestalls our empathy. Whatever, it was hard to tell, ultimately, how affected she was by the revelations of her family life. The emotion Kaplinsky showed was just the right amount of emotion; the excitement and upset were similarly measured. No wonder the autocue loves her.

Out of the box

— The second season of Suburban Shootout, a cartoon-like comedy about Middle England housewives behaving like warring Mafiosi, is under way. It’s funny and yet unfunny; camp and yet flat. Still, a show climaxing with a row of sheds getting blown to bits isn’t all bad.

— Why are ITV1 letting Jim Davidson get away with saying homophobic rubbish to Brian Dowling on Hell’s Kitchen about sleeping in the girls’ bedroom and being assigned to pastry work? Dowling, at the time of writing, was being patient. If Davidson was spouting racist slurs, he’d be ejected super-quick.

— Apologies: I wrote yesterday an equal age of consent was attained in 1998. While the Commons voted for an equal age of consent in 1998, it was two years before it became law.

Editor's choice

• The 100 Best Films of the Decade
• 70 facts you didn't know about Marvel
• The 50 Biggest Movies Of 2010