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Spectroscopic fluorescence polarization (P) measurements have been used to investigate exciton dynamics in conjugated polymers. We apply photoluminescence anisotropy to ensembles of non-interacting organic semiconductor molecules to explore exciton migration. An experimental observation shows linearly decreasing P values as the emission wavelength increases in partially oxidized poly[2-methoxy-5-(2-ethyloxy)-1,4-phenylenevinylene] (MEH-PPV) ensemble molecules. We discuss the origin of the experimental data with a computational simulation and P values for single chromophore perylene diimide dye molecules. We propose that the physical mechanism responsible for this behavior is the presence of exciton confined and blocking states at blue-shifted emission sites, which arise from excitons in partially oxidized parts of MEH-PPV.