Rutgers University doctoral student, Helen Wasielewski, under the direction of Dr. Lee Cronk, will investigate the effects of social learning on accumulative social change. The researcher will focus specifically on comparing the effects of imitation (behavior copying) with emulation (copying of products of behavior). Using an experimental micro-society design, which is a laboratory method for simulating cultural generations, the research will (1) improve understanding of how different social learning mechanisms contribute to the evolution of cumulative culture; (2) develop new methods for studying cumulative culture; and (3) contribute to better understanding of human cognitive evolution.
The researcher will collect data by videotaping social information transfer in a laboratory setting. Subjects will be asked to construct a weight-supporting device using simple materials and their success will be evaluated by measuring the maximum weight that each constructed device is capable of supporting. The subjects will be videotaped as they work and the tapes subjected to a close analysis to determine the amount and success of information transfer under different social learning conditions. The researcher will focus on (1) the interactions between the type of learning used and the rate of accumulation of changes to culture, (2) the effects of different social learning mechanisms on the fidelity of information transmission, and (3) the efficacy of behavioral information transmission by emulation in the absence of direct access to the behavior itself (that is, by looking solely at successful device examples without being able to observe the behaviors that produced them).
This research is important because it will help social scientists to better understand the cognitive changes that were necessary in human evolution for people to develop and pass on complex cultural practices. It also will contribute to understanding how cultural information is transferred between individuals, which is of interest to those concerned with cultural variation and processes of change. Funding this research also supports the education of a social scientist.
The data collected from this research project suggest that behavioral information is required for culture to accumulate complexity. This is consistent with the hypothesis that imitation, which is defined as copying following observation, is required for human-like culture. In this project, we assigned individuals to groups, called microsocieties, and tracked how information was transmitted between group members. Each person in the group built a weight-bearing device from reed and clay, and we measured how successful these devices were by counting how much weight the device could hold. This task is unique because it may draw on some of the same skill set that our ancestors needed in creating tools, and is sufficiently difficult such that participants probably needed to learn from one another in order to solve it. Therefore, this research contributes to the study of tool-making and social learning by providing a template for a novel, complex method that can be used in the laboratory to better understand cultural evolution. In the current research, each microsociety group was assigned to one of four conditions. In some of these conditions, participants could watch others building devices, whereas in other conditions they could see only the completed devices that were created. What we found is that groups able to observe others building devices, in contrast to those who saw only completed devices, show evidence of successive improvement. This finding suggests that in order to improve their devices participants needed to watch others making their devices -- that is, it was not sufficient for participants to see the completed device alone. The significance of this finding is that it supports the idea that imitation is important for information to accumulate. Since humans alone seem to regularly practice high-fidelity imitation, this difference in the use of imitation might be responsible for the difference in the degree of complexity between human and non-human cultures. By supporting the imitation hypothesis for cultural evolution, these results also are relevant to understanding the timing of complex cognition in our evolutionary history. These results therefore contribute to understanding the dynamics of culture transfer and one of the fundamental differences between humans and non-human animals.
