Activation volumes for chromophore reorientation were measured for a series of guest-host polymeric materials, indicating a significant coupling between chromophore motion and the glassy alpha and beta relaxation dynamics of the polymer host. The specific systems studied were formed by individually dissolving N,N-dimethyl-p-nitroaniline (DpNA), 4-(dimethylamino)-4＇-nitrotolane (DMANT), 4-(diethylamino)-4＇-nitrotolane (DEANT), and 1-((4-(dimethylamino)phenyl)ethynyl)-4-((4-nitrophenyl)ethynyl)benzene (DMAPEANT) in poly(methyl methacrylate) (PMMA), poly(ethyl methacrylate) (PEMA), and poly(isobutyl methacrylate) (PiBMA). In each of these systems, the isothermal, sub-T-g decay of the second-order optical susceptibility chi((2)) was monitored as a function of pressure using second harmonic generation. In each system, the observed decay of chi((2)) was represented by a stretched exponential equation from which the decay time tau(0) and decay distribution width beta(KWW) were determined. For each dopant molecule, the decrease in activation volume with the increasing size of the polymer host＇s alkyl side group and the pressure dependence of beta(KWW) were indicative of partial coupling between chromophore rotation and the glassy beta relaxation dynamics of the polymer host.