  Lock-in feedback circuits are routinely used in physics laboratories all
around the world to extract small signals out of a noisy environment. In a
recent paper (M. Kaptein, R. van Emden, and D. Iannuzzi, paper under review),
we have shown that one can adapt the algorithm exploited in those circuits to
gain insight in behavioral economics. In this paper, we extend this concept to
a very subjective socio-philosophical concept: the concept of beauty. We run an
experiment on 7414 volunteers, asking them to express their opinion on the
physical features of an avatar. Each participant was prompted with an image
whose features were adjusted sequentially via a lock-in feedback algorithm
driven by the opinion expressed by the previous participants. Our results show
that the method allows one to identify the most attractive features of the
avatar.
