"You find these personality traits that not too long ago we thought were uniquely human, and now they're popping up early in the evolution of vertebrates," linkurl:Ingo Schlupp,;http://www.ou.edu/cas/zoology/Schlupp.htm an evolutionary ecologist at the University of Oklahoma in Norman who was not involved in the study, told __The Scientist__. Manica's team also found that both leader and follow fish, when paired, responded to each other's movements, which led to stronger leaders, more faithful followers, and, ultimately, greater foraging efficiency -- a phenomenon driven by what the authors call "social feedback." "The behavior you get from the pair is totally different from what you see in individuals, which is the result of this feedback," Manica said. The same general principles should apply in humans, too. In human economics and management studies, it is well known that leader-follower interactions can greatly impact group dynamics and productivity. "The fundamental rules that lead to compromise and synchronized activities ought to be there [in humans]," Manica said. The study's "only minor shortcoming," noted Schlupp, is that Manica's team only tested fish duos rather than larger shoals. Still, "there's no reason why [social feedback] shouldn't be happening in larger groups," said Manica. "We started playing with three individuals, and the story doesn't seem very different. The mathematics is just very messy." A study by linkurl:Jens Krause;http://www.fbs.leeds.ac.uk/staff/profile.php?tag=Krause of the University of Leeds in the latest issue of__ linkurl:Behavioral Ecology;http://beheco.oxfordjournals.org/cgi/content/abstract/20/1/165 __validates Manica's findings in somewhat larger groups. Krause created quartets of guppies (__Poecilia reticulate__) consisting of all bold individuals, all shy individuals, or two of each temperament, and showed that the mixed personality shoal had the greatest foraging success. Together, these studies provide a potential mechanism for maintaining individual-level variation in behavioral traits related to personality, Manica said. Too many cooks in the kitchen, it seems, can spoil the broth -- or at least the fish soup, in this instance. __**Editor's note**: Watch out for another story about what threespine sticklebacks are teaching us about evolution in the upcoming February issue of __The Scientist__. Image: flickr/Uli1001's photostream **Related stories:__***linkurl:"Big cross" lands sticklebacks in the spotlight;http://www.the-scientist.com/article/display/15032/ [8th November 2004] *linkurl:Three-spined sticklebacks;http://www.the-scientist.com/article/display/20110/
[21st December 2001]
