Document Type


Degree Name

Master of Arts (MA)



Program Name/Specialization

Developmental Psychology


Faculty of Science

First Advisor

Kim P. Roberts

Advisor Role



An individual’s ability to accurately monitor source (attribute known or remembered information to its particular source or origin) develops gradually throughout childhood. Along with task difficulty (i.e., delay between encoding and retrieval), source similarity is among the utmost hindrance to individuals’ ability to accurately monitor source; specifically, the greater the similarity between sources the more difficult source monitoring judgments have been found to be, and the smaller similarity between sources (i.e., the greater number of differences between sources) the more accurate source monitoring judgments have been found to be. The similarity effect has been said to apply to all age groups, and has been assumed to be especially detrimental for young children. The present research looks further into the issue of source similarity, and suggests that the similarity effect may not be as generalizable as claimed. Specifically, although adults benefit most from dissimilar sources (as the similarity effect predicts), what may be paramount for young children (rather than more differences between sources) are few (at least one) but distinct differences between sources. The present study aims to begin consideration in this area by focusing on visual information. An experimental research design was used to assign 99 participants of different age groups (3-5, 6-8, 18-21) each to two different source-monitoring conditions. Each condition contained two actors, and the number of visual cues that differed between actors varied for each of the conditions (one-cue and five-cues). Specifically, the number of visual cues was manipulated such that one pair of actors displayed one distinct visual difference, and the other pair displayed five visual differences. After a short distractor task, participants were interviewed and asked to make source-monitoring judgments about actions performed by the actors within each of the two events. Data were collapsed and analyzed by age group. In line with past literature, an overall/general developmental progression was found to exist in participants’ ability to make accurate source judgments. Contrary to the present proposed theory, there was no significant interaction between age and cue condition; individuals of all age groups were found to be more accurate in the five-cue condition than in the one-cue condition (as predicted by the similarity effect). The obtained results in relation to the proposed theory were discussed. Understanding the way that individuals use cues to monitor source can help us further understand developmental differences in source monitoring, clarify the basic mechanisms involved, and highlight other aspects of children’s memory development. In addition, basic research questions concerning the nature of children’s source-monitoring errors may be particularly important to understanding the caveats surrounding forensic interviews with young children.

Convocation Year


Convocation Season


Included in

Psychology Commons