Primacy effects in animal memory and human nonverbal memory

Evidence for primacy effects in animals’ list memory is accumulating, despite assertions that these primacy effects may be list-initiation-response artifacts (D. Gaffan, 1983; E. Gaffan, 1992). This evidence comes from list-memory experiments with pigeons and monkeys in which primacy changed with retention interval, experiments with monkeys in which primacy correlated with list length, and experiments with monkeys in which there were no list-initiation responses. Furthermore, there is growing evidence that animal memory is similar to, at least, the nonverbal part of human memory. This evidence comes from human nonverbal-memory experiments in which primacy changed with retention interval (similar to animals) when using kaleidoscope or snowflake stimuli, and similar experiments in which the verbal/nonverbal component was manipulated. Conditions conducive for obtaining primacy effects are discussed.