Do chimpanzees seek explanations? Preliminary comparative investigations

Canadian Journal of Experimental Psychology, Jun 2001 by Daniel J Povinelli, Sarah Dunphy-Lelii

Children

METHOD

Participants. The participants were 48 preschool children recruited from the Lafayette, Louisiana area, whose parents gave their written, informed consent for their participation. There were 16 three-year-olds (3647 mos), 16 four-year-olds (48-59 mos), and 16 fiveyear-olds (60-71 mos). The children were primarily from working- and middle-class families of Caucasian, Black, Hispanic, and Asian descent. In addition to the final 48 participants, the data of two five-year-olds were discarded because of an experimental error in recording their sessions.

Apparatus. Three cylindrical blocks were decorated as trees. Two of these blocks could stand upright whereas one (the sham block) could not. A flat rectangular box served as the platform. As with the apes, most of the surface of the box was covered with a thick, irregular mat upon which the trees could not be made to stand. However, the platform contained three circular areas in which the blocks could be stood.

Procedure. After a warm-up period with the experimenter, the children were separately ushered to a testing area where they were introduced to the trees and the platform. The children were told that they were going to play a game in which they could build a forest with the trees, and were then shown how to stand up the blocks. The children were encouraged to stand up all three trees without any direct assistance from the experimenter. After they did so, they were rewarded with brightly coloured stickers. After a brief distraction, during which the experimenter took the trees down, the children were encouraged to stand up the trees for a second time, and were again rewarded with stickers. Finally, while the children were distracted, the experimenter covertly replaced one of the three functional blocks with the sham block. The children were again told to build the forest. This third trial lasted a maximum of 120 s, during which time the experimenter appeared distracted (reading a book) to discourage the children from seeking direct assistance. If the children insistently appealed to the experimenter, her verbal responses took the form of general encouragement and support (e.g., "Can you get the trees up?", "You're doing a great job!", "Hey, look at that!"). After the 120 s had elapsed, or as soon as the children refused to try any further, the experimenter picked up the sham tree and asked them, "Why won't it stand up?"

Videotape coding. The tapes were coded by a main rater (who coded all of the children) and by a reliability rater (who coded 25% of the children) after reading a set of written instructions which asked the following: "Did the child look at the bottom of the [sham] tree?", "Did the child touch the bottom of the [sham] tree?", "Did the child switch the [sham] tree to another white circle?" (all rs = 1.00). The main rater also produced a transcript of all of the spontaneous utterances of the children during the trial. Two additional raters independently coded each of these transcripts for whether the children (a) described the ongoing state of affairs (i.e., "It keeps falling down"), (b) asked "Why?", (c) used mentalistic terminology to describe the tree ("It doesn't want to stand up"), and/or (d) offered a physical cause as an explanation for the sham block's failure (i.e., "Because that's flat and this is down and this is up"). Kappas for these measures ranged from 0.86 to 1.00.