Skip to main content
. 2012 Feb 6;109(9):3588–3592. doi: 10.1073/pnas.1108517109

Fig. 3.

Fig. 3.

Photo showing Ayumu standing up and assessing his mother's situation by peaking through the hole in the opaque panel wall separating the two booths. He was the only chimpanzee to assess so actively his partner's situation and to select and transfer the appropriate tool to his partner in the “cannot see” condition.