The dynamics of polarization competition in vertical-cavity surface-emitting lasers (VCSELs) is investigated experimentally. The fluctuations of the linear polarization components of the field, which are strongly anticorrelated with a non-Gaussian statistics, are characterized. The analysis of the data indicates that the competition is well reproduced by a simple Langevin description, with a two-well quasi-potential. The Kramers times and the statistics of the mode jumping are obtained and compared with the observed phenomena.