Contributions of declarative memory and prior knowledge to incidental L2 vocabulary learning

The bulk of second language (L2) vocabulary learning happens incidentally through reading (Rott, 2007; Webb, 2008), but individual differences, such as prior knowledge, modulate the efficacy of such incidental learning. One individual difference that is strongly predicted to play a role in L2 vocabulary is declarative memory ability; however, links between these two abilities have not been explored (Hamrick, Lum, & Ullman, 2018). This study considered declarative memory in conjunction with varying degrees of prior knowledge, since declarative memory may serve a compensatory function (Ullman & Pullman, 2015). L2 Spanish learners completed measures of prior Spanish vocabulary knowledge, declarative memory ability, and incidental L2 vocabulary learning. The results suggest that better declarative memory predicts better immediate learning in general and better vocabulary retention two days later, but only for those with more prior knowledge, consistent with the Matthew Effect previously reported in the literature (Stanovich, 1986).