Daytime TV: Who the hell am I?

Professor Robert Winston invited us to find out who we are over two nights (The Big Personality Test: A Child of Our Time Special, BBC One, Sunday 30 May and Monday 31 May, 9pm). He was worried that Britons gaze into the bathroom mirror every morning and exclaim, at the sight of their reflection, "Who the hell are you?"

The Roman physician Galen said that the human temperament was divided into four types: sanguine, choleric, melancholic and phlegmatic. How innocent that seems from our sophisticated perspective. Thanks to the progress made by science, we now know that the personality falls not into four but five categories: openness, conscientiousness, extroversion, agreeableness and neuroticism.

So there's no excuse for misunderstanding one another ever again. But, just to make sure, we need to get rid of all those words that may complicate this simple scheme. You can find a lot of them in literature, so there's another reason to be rid of this troublesome subject. An online survey helped you to find out which of the five terms applied to you. If none did, then don't worry. They don't apply to any of the characters in EastEnders either. And look how interesting they are.

Understanding our personalities helps us to make decisions, said Robert. Not so, said his co-presenter, Sophie Raworth. It is our personalities that dictate our decisions. Surrounded by children, Robert smiled. But his moustache twitched slightly. Sophie demonstrated that personality was destiny by visiting magazine company IPC Media. Those staff of an extrovert disposition were drawn to advertising, those who were agreeable to distribution, and those who were neurotic to administration. Sophie astounded viewers by saying that if you were conscientious, you were more likely to be successful.

Back in the studio, the 25 children whose development is being closely monitored by the programme were asked to paint a portrait of Robert. They were told to paint by numbers, then, halfway through, they were given the choice to abandon that approach if they so wished. Those who did were seen as more open, those who didn't were seen as conscientious, or possibly neurotic. Robert seemed pleased with the more psychedelic versions of himself. It was all good fun and very much in the style of a Saturday morning children's TV show from the 1970s, with content to match.

If you wanted a more considered view of who we are, then Michael Mosley is your man (The Story of Science: Power, Proof and Passion - Who Are We? BBC Two, Tuesday 1 June, 9pm). First stop, ancient Egypt. When mummifying a corpse they removed the brain. Humanity lay in the heart. And it was much more than mere flesh and blood. Fast forward to 17th-century France. Michael is in the Hall of Mirrors at Versailles. He lingers there awhile admiring his reflection before suddenly remembering he's presenting a programme. "We are individuals", he announces hastily, "defined by desires, ambitions and destinies." "Destinies"? Doesn't that rather detract from the notion of choice, which is central to the idea of the individual?

For Descartes, it was doubt that revealed our humanity. Seeing a statue of Neptune move towards him powered by water, the oven-dwelling philosopher conceived the idea that the human body was a machine moved by a soul. This was one example of how developments in technology provided metaphors for understanding ourselves. The railway is another. It was a means of thinking about the myriad connections in the brain. Sir Fred Hoyle's inspiration for his steady-state theory of the Universe, where everything repeats itself endlessly, came from the film Dead of Night (1945). Michael took a brain in his hands. "It's amazing to think that this was once alive with thoughts and feelings." He cut it in half. The inside of the two hemispheres looked like a sliced mushroom.

From a lab to a zoo. Michael met Batty, an orang-utan. He was trying to recreate Darwin's encounter with an orang-utan called Jenny. It was on the basis of his observations that Darwin made his claim regarding the similarity of human and animal expressions. If Jenny didn't get her apple, she would roll around and cry. Batty was more evolved. He wasn't interested in interacting with Michael and let him know by a downward explosion of flatulence that left our hero choking and reeling around the room.

All this added up to the proposition that our knowledge of ourselves is only provisional. There is always something we don't know. We couldn't have had a clearer demonstration of that than the bewilderment surrounding Derrick Bird's murder of 12 people before ending his own life. It will take more than two nights to explain that.