Category: Kevin N. Laland

Kevin N. Laland

The teaching conundrum had been solved. Teaching evolves where the costs are outweighed by the inclusive fitness benefits that result from the tutor’s relatives being more likely to acquire the valuable information. Teaching is not favored when the pupil can easily acquire the information on their own or through copying others. Nor is it favored when imparting traits that are difficult to learn, as teachers generally do not possess the information to pass on to their relatives. These restrictions typically lead to few circumstances under which teaching would be efficacious. Models that allow for cumulative cultural knowledge gain, however, suggest that teaching evolved in humans despite, rather than because of, our strong imitative capabilities, and primarily because cumulative culture renders otherwise difficult-to-acquire valuable information available to teach. The analyses suggest that human teaching and cumulative culture evolved together, through mutual reinforcement.

Kevin N. Laland

Strategies that did well in competition with other strategies were not, however, those that maximized the returns to agents. Rather, we found a strong inverse relationship between the mean fitness of individuals in populations containing only one strategy, and that strategy’s performance in the tournament. This finding illustrates the parasitic effect of strategies that rely heavily on OBSERVE. Strategies using a mixture of social and asocial learning are vulnerable to being outcompeted by those using social learning alone, which may result in a population with lower average returns. These findings are evocative of an established rule in ecology; this specifies that, among competitors for a scarce resource, the dominant competitor will be the species that can persist at the lowest resource level. An equivalent rule may apply when alternative social learning strategies compete: the strategies that eventually dominates will be the one that can persist with the lowest frequency of asocial learning.

Kevin N. Laland

The first finding that jumped out at us was that it is possible to learn too much ! In the tournament, investing lots of time in learning was not at all effective. In fact, we found a strong negative correlation between the proportion of a strategy’s moves that were INNOVATE or OBSERVE, as opposed to EXPLOIT, and how well the strategy performed. Successful strategies spent only a small fraction of their time (5-10%) learning, and the bulk of their time caching in on what they had learned, through playing EXPLOIT. Only through playing EXPLOIT can a strategy directly accrue fitness. Hencem every time a strategy chooses to learn new behavior, be it through playing INNOVATE or OBSERVE, there is a cost corresponding to the payoff that would have been received had EXPLOIT been played instead. This implied that the way to get on in life was to do a very quick bit of learning and then EXPLOIT, EXPLOIT, EXPLOIT until you die. That is a sobering lesson for someone like myself who has spent his whole life in school or university.