For the study, published in the journal Evolution and Human Behaviour, the team investigated the role of memory in small and large populations using a neutral agent-based model that simulates human interactions. They found that long-term cultural memory tends to reject rather than preserve local unique inventions, and that an increase in memory is the equivalent of increasing the affinity or relationship between agents in the model, which blocks influences from outside the group.
Agents’ affinity refers to not only how far apart physically they are, but could also refer to the relational distance between two family members, for example, or degree of friendship in a social network. According to the study, increasing cultural memory reduces the size of the ‘invention pool’ and the few alternatives that do exist are not taken up quickly enough to have much of an impact, if at all.
The research team conclude that increasing memory may actually decrease the visibility of an innovation, because of the wide number of choices cultural memory makes available to the agents. But in the case where agents have shorter memory innovation has a much greater impact, and researchers note that affinity is key to whether that innovation will be widely adopted or not through the agent’s social network.
The findings could be applied to a large variety of different innovations from political or scientific ideas to mobile phones or media formats. Further research could include the influence of bias on the spread of innovation, and compare the model to actual scenarios such as the London elections.
Ideally, for innovation to spread widely the agents would need to have little to no cultural memory and be highly interconnected. Starting with a small group of agents an innovation could make its mark on the population early on, but over time as the group’s memory increases it would lower the level of impact that innovation would have.
Bentley, R.A., Caiado, C.C.S., Ormerod, P. (2014) Effects of memory on spatial heterogeneity in neutrally transmitted culture. Evolution and Human Behavior. (in press)