«Education, then, beyond all other devices of human origin, is the great equalizer of the conditions of men, the balance wheel of the social machinery.»
– Horace Mann, 1848
While Horace Mann’s famous quote that education is the great equalizer is well known in educational circles, sometimes in education the rich get richer and the poor get poorer. It is well-established by now that some educational interventions appear to improve learning outcomes not because they benefit all of the students but because they benefit students who already had a good academic performance. This phenomenon, sometimes referred to as the Matthew effect, widens the gap between students with better and worse learning outcomes rather than shrinking this gap and providing opportunities that benefit all students. Now, new research examining the effect of prior knowledge on new learning within a domain confirms this rich-get-richer effect.
In a recent set of experiments, Witherby and Carpenter (2021) investigated whether students’ prior knowledge would predict their ability to learn new information about a certain topic. Across three experiments, the researchers measured University students’ prior knowledge in two independent fields: football and cooking. Later, the students learned new information by attempting to answer questions in each of the two domains and receiving the correct responses as feedback. Importantly, the information in these questions was plausible but false. The researchers chose to use plausible but false information to ensure that the students could not have known that information previously, and thus could examine new learning. Of course, correct answers were extremely rare because the information in the questions was made up by the researchers. After the students provided their guesses, they received feedback showing them the correct answer, and then indicated how certain or uncertain they were that they would remember the correct answer later. After this learning phase was complete, the researchers assessed the students’ knowledge acquisition in a self-paced final test in which they answered the same questions.
In all three experiments, prior knowledge predicted new learning, but only in the specific domain the student already mastered. In other words, when students had higher prior knowledge about football, they were better able to learn new (false) information about football, but not about cooking and vice versa. Because prior knowledge about a given domain only predicted learning in that specific domain, these results indicate that students with more prior knowledge are not simply better learners than those with less prior knowledge. The researchers also examined the amount of time that students spent reviewing the feedback and found no differences between those with higher prior knowledge and those with lower prior knowledge: students with differing levels of prior knowledge spent on average the same amount of time reviewing the answers, demonstrating that the attention paid to the material is not the sole predictor of success when it comes to knowledge acquisition in both groups. Finally, results indicated that prior knowledge affected students’ opinions about how well they would remember the information later—those with greater prior knowledge thought they would remember the new information better than those with lower prior knowledge—indicating that students may use their own prior knowledge as a cue to determine how well they are learning new information.
Why is it that students with greater prior knowledge within a domain learned more new information in that domain compared to those with lower prior knowledge? Results from the third experiment in the article provide some clues. In Experiment 3, students indicated how curious they were to know the answer to each question before receiving feedback during the learning phase. The researchers found that students with higher levels of prior knowledge were more likely to show greater curiosity about the answer to the question. Significantly, this effect was domain-specific. Prior knowledge in one area (e.g., football) did not predict greater curiosity about the other area (e.g., cooking). Of course, prior knowledge could have sparked curiosity about a topic, or curiosity about a topic could have led to greater prior knowledge in the first place. More research is needed to understand these complex relationships.
These findings are consistent with the idea that the rich get richer and the poor get poorer; the results suggest that students with lower levels of foundational knowledge in a subject will tend to learn less than students who have higher levels of knowledge, in the same amount of time. Other research on prior knowledge has suggested that students with greater prior knowledge may benefit more from some learning tactics. For example, Woloshyn and colleagues (1992) found that students with high prior knowledge benefited more than those with low prior knowledge from elaborative interrogation, an effective learning process during which students generate “how” and “why” questions and then come up with the answers to those questions.
While many may view education as the great equalizer, students who are less knowledgeable in an area may need more attention to build upon their foundational knowledge in order to benefit from the same teaching strategies that help other students and prevent the widening of knowledge gaps during lessons.
Witherby, A. E., & Carpenter, S. K. (2021). The rich-get-richer effect: Prior knowledge predicts new learning of domain-relevant information. Journal of Experimental Psychology: Learning, Memory, and Cognition. Advance online publication. http://dx.doi.org/10.1037/xlm0000996
Woloshyn, V. E., Pressley, M., & Schneider, W. (1992). Elaborative-interrogation and prior-knowledge effects on learning of facts. Journal of Educational Psychology, 84(1), 115-124.