Last week I commented on the view of Matthew Bown (TLS April 10 2015) that art works appeal to us in the way that saintly relics do: as traces of admired agents. A related view has been advocated for some time by the psychologists George Newman and Paul Bloom. They hold that a good deal of artistic valuing can be explained in terms of what is called magical contagion "people believe, perhaps unconsciously, that a person’s immaterial essence... can be transferred to an object through physical contact" (PNAS 2014).
On this view then people value art works partly because they think ("perhaps unconsciously" as they put it) that the qualities of the artist will be transmitted to them. But their view is susceptible to the same criticism I brought against Bown: it does not distinguish the value of something considered as a trace of an agent from the value of something considered as a trace of agency.
Imagine Picasso in Paris one cold winter, who possesses a canvas by a not very talented acquaintance, and wears it that winter as an eccentric form of insulation. It is hard to imagine an art object more intimately physically related to Picasso than this one. Would it fetch the price of a sketch by Picasso done with a pencil and never actually touched by his body? Pretty surely not. It's not extent, or intimacy or duration of contact that matters but the kind of contact. The contact Picasso had with his sketch via the pencil is valued much more highly than the contact he had with the canvas. Perhaps Bloom and Newman will agree: it is kind of contact that matters for the triggering of the contagion effect when it comes art works. But then the contagion theory starts to look much more like another theory they offer: that original works are valued because they are the upshot of admirable processes. For the kind of contact that makes the Picasso sketch valuable is exactly that kind of contact: while the physical relation is fleeting and indirect, it manifests qualities of artistic skill. I don't think that their theory of performance value is quite right as it stands but it is closer to getting at what is valuable about an original work of art. It also does not make the valuing of artistic originals seem wholly irrational, in the way that the contagion theory does.
Bloom and Newman are probably right that something like the idea of contagion plays in our valuing of all sorts of things from celebrity possessions through autograph copies of book manuscripts to Picasso's signature. But we need to recognise that there is a special and distinct kind of value that art works and skilfully made things of all kinds possess: their ability to manifest skills of which they themselves are the causal upshot.