One of the attractive feature of Self-Organizing Maps (SOM) is the so-called "topological preservation property": observations that are close to each other in the input space (at least locally) remain close to each other in the SOM. In this work, we propose the use of a bootstrap scheme to construct a statistical significance test of the observed proximity among individuals in the SOM. While computer intensive at this stage, this work represents a first step in the exploration of the sampling distribution of proximities in the framework of the SOM algorithm.