To trust or not to trust your friends

January 30, 2007

Sometimes it is better to follow the advice of others rather than your own mind even though you seem to have things under control. Not only humans but also fish follow this doctrine as shown by ecologists Jörgen Johnsson and Fredrik Sundström of Göteborg University, Sweden, in the journal Ethology.

They allowed European minnows to learn the correct route through a maze to obtain food in the presence or absence of a predatory brown trout. Then a naïve minnow joined the group on later trials either in the presence or absence of the trout. Naïve fish without the predator were only half as successful in finding the food when their group of mates had been pre-trained with the predator.

Therefore, in this situation the naïve fish would have been better off not trusting its group mates which had outdated information on predation risk. However, Johnsson and Sundstrom also found that regardless of predator treatment, the foraging success of the naïve fish improved as the skills of their experienced group mates increased.

Johnsson and Sundström suggest that an animals individual learning ability can not always keep up with rapid changes in the environment and that is why using social information, even if it is not always perfect, may still be more beneficial in the long run than relying only on yourself.

Source: Blackwell Publishing Ltd.