Art review: Royal Society of Portrait Painters Annual Exhibition, The Mall Galleries, London

There is something curiously lacklustre about much of this show. Why? It is not that the majority of these representational portraits – there are more than 200 of them in all - are not good examples of their kind.

After all, many of these painters are professionals, and this exhibition exists to sell their works. They make money out of doing a good job, and they would not be exhibiting here had their works not reached a certain high standard of technical competence.

It is rather something to do with the nature of portraiture of this kind and its particular history. Portraiture of this kind often exists to please the sitter by creating a recognisably gratifying likeness. It is not in the business of exposing the dark underbelly of life. The consequence of this is that much of it feels rather skin-deep.

It lacks the tension of genuine engagement, that sense that the painter is wrestling with the subject of his painting. What is more, to buy one's own painted likeness requires considerably greater investment than, say, a photograph, so those who sit to a portrait painter often tend to be the materially advantaged and their pretty little Kitties and Henriettas.

The consequence of all this is that the new portrait often feels like a fairly predictable, though somewhat debased, variant upon the history of portraiture, a distant memory of, say, Van Dyke or Kneller and on, which exists to reward the memorable with a memorable likeness. Many of the affable likenesses in this show could have been in last year's show. Few of them give us evidence of singularly exciting talent, a talent at work in 2013. Celebrities come and go. Here is Alan Bennett, as painted by Sam Dalby , the talent for bawdiness well concealed behind the matter-of-factness of the provincial schoolmaster.

The best of the works in this show are in a section devoted to a new prize for self-portraiture called 'Self'. Here, at last, the spirit of adventure seems to have sneaked in by a side door, though not too much adventure, it has to be said. Nothing to knock us dangerously off-kilter. Look, for example, at Robert and Renato Miaz's mist-like representation of a human head, so ghostly in its near-absence. This society began in a lusty shout of defiance against the elitism of the Royal Academy. That spirit of rebellion needs to be re-kindled.