Both photochemical alpha-cleavage of triplet benzoin (BZ) and hydrogen abstraction by triplet benzaldehyde (BA) from ground-state benzaldehyde produce geminate radical pairs of identical chemical structure. A search for "memory effects" in the chemically identical geminate radical pairs generated from different photochemical pathways was examined using the techniques of time-resolved electron spin resonance (TRESR) and time-resolved optical absorption spectroscopy. Photolysis of BZ in homogeneous organic solvents and in sodium dodecyl sulfate (SDS) micellar solutions leads to chemically induced dynamic electron polarization (CIDEP) of benzoyl and alpha-hydroxybenzyl radicals consisting of a strong emission (E) due to the triplet mechanism (TM) in the generation of electron polarization. Photolysis of BA in hydrogen-donating organic solvents results in a E/A (or E*/A) CIDEP pattern of alpha-hydroxybenzyl radicals due to the radical pair mechanism (RPM). In solvents which are poor hydrogen donors (benzene, acetonitrile) and/or at relatively high concentrations of BA, the photoreduction of triplet BA by ground-state BA generates benzoyl and alpha-hydroxybenzyl radicals, which manifest an E/A CIDEP spectrum assigned to RPM. Photoreduction of BA by KCNS in aqueous acetonitrile results in absorptive (A) CIDEP of alpha-hydroxybenzyl radicals, assigned to a rare case of RPM for which the g factor difference overwhelms the hyperfine interactions of the pertinent radical pair (the alpha-hydroxybenzyl and the (CNS)2.- radical). Computer simulation allows the estimation of the g factor of this inorganic polarized radical to be in the range 2.015 < g < 2.03. Under conditions of low occupancy number of BA, the photolysis of BA in SDS micellar solution displayed CIDEP spectra assigned to a spin-correlated geminate radical pair (SCRP) consisting of alpha-hydroxybenzyl and alkyl radicals of SDS. At a higher occupancy number, a different SCRP spectrum is observed and is assigned to a polarized alpha-hydroxybenzyl and benzoyl mdical pair. Computer simulation confirms all of the proposed assignments. Measurements of the decay kinetics of the alpha-hydroxybenzyl radical, observed by time-resolved absorption spectroscopy, show that the application of an external magnetic field of 0.30 T leads to a decrease in the rate of micellized geminate recombination in the photoreduction of micellized BA and to an increase in the rate of radical escape. No significant magnetic field effect was found on the decay of the alpha-hydroxybenzyl radicals produced from BZ. These results imply that radicals formed by alpha-cleavage of triplet BZ escape from micelles faster than the chemically identical geminate pair generated by the photoreduction of triplet BA by ground-state BA.