Making Our Presentations More Appealing
There is a recent study scheduled to be published in the Journal of Educational Psychology which addresses this question. And the answer the researchers found depends on the audience. Young learners (Grades 5 and 6) benefit the most with images that have a medium level of anthropomorhism while older students (high school) learn most efficiently with images that have a high level of anthropomorhism. The different degrees of human like features are illustrated in the following images on slides that are used for teaching blood platelets:
Adding decorations to figures increases the cognitive load on a learner which can be detrimental to learning. This apparently is the case for young learners who have no prior knowledge on this subject. Having a medium level makes the figure attractive enough to motivate students but without overloading. With young high school students (Grades 8 and 9), high anthropomorphism is required to make a significant difference in learning outcomes. And for senior high school students (Grades 11 and up), anthropomorphism still helps but there is no significant difference between high and medium levels of anthropomorphism.
What happens with very young children seems easily explained by balancing aesthetics with cognitive load. Young learners are very susceptible to distraction so it it important not to overdo the embellishment. For young high school students, the highest level of anthropomorphism works best. But as students get older, there are no more additional benefits by adding more to an image. One can perhaps extrapolate this to even older students (college and graduate school). At this stage, students may begin to view these drawings as simply childish.