Wet Braini­acs

Newsweek International - - CONTENTS - BY KRISTIN HUGO @Kristin­hugo

’ : dol­phins does it take to screw in a light­bulb? Zero, be­cause there are no dim bulbs in the dolphin world.

Ce­taceans, the group of an­i­mals that in­cludes dol­phins and whales, are in­tel­li­gent, big-brained crea­tures that form friend­ships and so­cial tra­di­tions sim­i­lar to those of hu­mans. They also play, babysit, hunt co­op­er­a­tively and teach one an­other how to do things. “They have sig­na­ture whis­tles,” says study co-au­thor Michael Muthukr­ishna, an as­sis­tant pro­fes­sor of eco­nomic psy­chol­ogy at the Lon­don School of Eco­nom­ics. “They ac­tu­ally have names for each other.”

A new study pub­lished in Na­ture Ecol­ogy and Evo­lu­tion looks at how the size of an an­i­mal’s brain af­fects its so­cial ac­tiv­ity. Re­searchers at the Univer­sity of Manch­ester, the Univer­sity of Bri­tish Columbia, Stan­ford Univer­sity and the Lon­don School of Eco­nom­ics and Po­lit­i­cal Sci­ence gath­ered data from years of stud­ies on the brain sizes of 90 species of whales and dol­phins, as well as from stud­ies by field sci­en­tists on the breadth of so­cial be­hav­iors of wild dol­phins and whales, such as us­ing lan­guage, shar­ing goals, teach­ing one an­other, act­ing with em­pa­thy and mak­ing de­ci­sions based on con­sen­sus. By as­sign­ing a value to each species based on how of­ten it en­gaged in th­ese so­cial ac­tions, the sci­en­tists were able to plot the so­cia­bil­ity and brain size. The graph showed that as brain size in­creased, so did the breadth and num­ber of so­cial be­hav­iors.

The find­ings may teach us about our­selves as well. They sug­gest that the evo­lu­tion of hu­man brain size and our so­cial in­stincts may be linked. How­ever, dol­phins are not about to evolve into bipedal, an­thro­po­morphs with ad­vanced so­ci­eties like those of hu­mans. Although whale and dolphin so­ci­eties are sim­i­lar so­cially to those of hu­mans, the aquatic an­i­mals lack cer­tain abil­i­ties nec­es­sary for hu­man evo­lu­tion. They can com­mu­ni­cate well and hunt ef­fi­ciently, but they do not have thumbs, which are re­quired to make com­plex tools. Fur­ther­more, the abil­ity to cook was an im­por­tant mile­stone in hu­man evo­lu­tion, and this is an ad­van­tage we will al­ways have over dol­phins. “They will never dis­cover fire,” says Muthukr­ishna, “be­cause it’s very dif­fi­cult to light a fire un­der­wa­ter.”

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