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Chim­panzee San­tino achieved inter­na­tional fame in 2009 for his habit of gath­er­ing stones and man­u­fac­tur­ing con­crete pro­jec­tiles to throw at vis­i­tors of Furu­vik Zoo in Swe­den. A new study shows that Santino’s innovativeness

when he plans his stone-​throwing is greater than researchers have pre­vi­ously observed. He not only gath­ers stones and man­u­fac­tures pro­jec­tiles in advance; he also finds inno­v­a­tive ways of fool­ing the vis­i­tors. The recently pub­lished study (PLoS One, May 9) was car­ried out by Math­ias Osvath and Elin Kar­vo­nen from Lund University.

The new study looked at the chimpanzee’s abil­ity to carry out com­plex plan­ning. The case study shows how humans’ clos­est rel­a­tives in the ani­mal king­dom appear to be able to plan to deceive oth­ers, and that they can also plan their decep­tion inven­tively. The behav­iour of the chim­panzee San­tino is of par­tic­u­lar inter­est because it is done while the humans to be deceived are out of sight. That means that the chim­panzee can plan with­out hav­ing imme­di­ate per­cep­tual feed­back of his goal — the vis­i­tors to the zoo — to aid in his planning.

The sub­ject of the study is San­tino the chim­panzee, who achieved inter­na­tional fame in 2009 for his habit of gath­er­ing stones and man­u­fac­tur­ing con­crete pro­jec­tiles to throw at vis­i­tors from the safety of his enclo­sure at Furu­vik Zoo north of Stock­holm. His behav­iour was reported as an exam­ple of spon­ta­neous plan­ning for a future event, in which his psy­cho­log­i­cal state was vis­i­bly quite dif­fer­ent from that of his sub­se­quent aggres­sive displays.

Pre­vi­ously, such cog­ni­tive abil­i­ties had been widely believed to be restricted to humans. The new study sought to col­lect more detailed data on Santino’s projectile-​throwing behav­iour over the course of the 2010 zoo sea­son. In this study, the chim­panzee con­tin­ued and extended his pre­vi­ous behav­iour of caching pro­jec­tiles for later use in aggres­sive throw­ing dis­plays. The new behav­iour involved inno­v­a­tive use of con­ceal­ments: both nat­u­rally occur­ring ones and ones he man­u­fac­tured from hay. All were placed near the vis­i­tors’ area. This allowed San­tino to throw his mis­siles before the crowd had time to back away.

The first hay con­ceal­ment was made after the zoo guide had repeat­edly backed vis­i­tors away when the chim­panzee made throw­ing attempts. All con­ceal­ments were made when the vis­i­tors were out of sight, and the hid­den pro­jec­tiles were used when they returned. In order to make the hay con­ceal­ments the chim­panzee had bring the hay from the inside enclosure.

Over the course of the sea­son, the researchers observed that the use of con­ceal­ments became the chim­panzees pre­ferred strat­egy. More­over, San­tino com­bined two decep­tion strate­gies con­sis­tently: hid­ing pro­jec­tiles and inhibit­ing the dis­plays of dom­i­nance that oth­er­wise pre­ceded his throws.

The new find­ings sug­gest that chim­panzees may be able to rep­re­sent the future behav­iour of oth­ers while those oth­ers are not present. It is also crit­i­cal that the chimpanzee’s ini­tial behav­iour pro­duced a future event, rather than merely prepar­ing for one that had reli­ably occurred before. This in turn, sug­gest a flex­i­ble plan­ning abil­ity which, in humans, relies on cre­ative re-​combining of mem­o­ries, men­tally acted out in a ‘what if’ future scenario.

The above news item is reprinted from mate­ri­als avail­able at Lund Uni­ver­sity via Alpha­Galileo Foun­da­tion. Orig­i­nal text may be edited for con­tent and length.

(Source: News­room Lund Uni­ver­sity, 10.05.2012)