There is a particular facial expression I am trying to understand today. It requires big eyes, held still and wide, looking up at you; eyebrows lifted to meet each other, like a frown pulled up towards the forehead; head bowed, leaning sideways.

Sometimes there is a welling tear. It is common among dogs, television movie orphans, Hollywood actors talking about how great it was to work with each other in their new movie and “children in need” in newspaper adverts asking you to give a dollar a day.

For the dog, this expression means “don’t hurt me, I love you”. In the Oxfam advert, and the orphan movie, it says “feed me”. I wonder whether this expression dates back to before we split with the chimpanzee; maybe it dates back to when we split with dogs.

When my nephew was four, he had a season during which he would remain silent, looking at us, unblinking with big eyes wide, eyebrows up. We would all coo and his mum would check his temperature. One day, I caught him standing on a chair in front of the bathroom mirror practicing this look.

The practised version of this expression has found a word in English: disingenuous. This word is the opposite of the word ingenuous, present usage of which dates back to the days of John Lilburn. He was a member of the Levellers, a 17th-century English political party, and the word freeborn is associated with him. Ingenuous comes from these heady days and referred to a new kind of man “with the virtues of freeborn people, of noble character, frank”.

Presumably this new man felt he no longer needed to rearrange his features to appease the powerful. Hangdog.

Some historians think that Lilburn’s idea of a freeborn man could have influenced the memorable phrase, in the American Declaration of Independence, “that all men are created equal, that they are endowed by their Creator with certain unalienable Rights”. These words were used to mount a defence against slavery in the United States. Much of what we think about today as our natural human rights derives from some of these ideas.

Until very recently, disingenuous was most often used as a synonym of calculating or cynical. In our spin-driven world, it has become a new word; it has come to mean pretending to be unaware.

In our visual age of two-second immediacies, a facial expression has perfected itself: the only reality is this moment -- nobody has time to check back, to see the history of your promises or wade through the sheer volume of internet material. So an expression of perfect, innocent earnestness will persuade people to see you as such.

This is Tony Blair’s permanent expression and it has worked for him.

In the US, you see this expression everywhere. Pop Idol contestants always look like they are unaware that they are “star material”; many of my African fiction students at Union College in New York present this expression when some unbearable African reality presents itself in a scene read out loud or brought up for discussion. The expression is mostly absent in my creative writing class, where students feel free to be sarcastic or sleepy.

If we did split from the dog 10-million years ago, we still retain the fear of hurting the puppy. The reason my students adopt this expression is because they have a hidden fear that I will one day point a finger at them and ask a question. They fear what they presume to be my “authenticity” -- a word I have come to dislike.

Talking to anybody here, in this capital of branding, even mentioning that you come from Africa makes people quickly put on a compassionately concerned expression, because the most prevalent image related to Africa is the Pity Face. This face announces a generalised concern that informs you that the person is a good person, who cares. It does not want details.

This is Brand Africa. No matter that last year the Kenyan stock exchange was one of the world’s best-performing bourses. Nothing we could possibly do can supplant the now fixed idea that we have nothing to sell or contribute except misery.

The New York Times has cultivated to perfection the prose twin of the disingenuous face: the Africa Opening Paragraph. Earlier this month: “Traveling to school in wobbly dugout canoes, Munalula Muhau and her three cousins, 7- and 8-year-olds whose parents had died from Aids, held on to just one possession: battered tin bowls to receive their daily ration of gruel.”

Why do I feel like laughing at this? Is this sort of melodrama about Africa a matter of policy for the Times editors? Such oft-repeated images amount to generalised and generic high-intensity pity created by real people found, who are presented without the self-supporting integrity of character and context that we have come to expect is our natural right.