Seeking help can be a highly adaptive behavior. From an evolutionary perspective, strategic help-seeking can significantly improve an individual's fitness. However, it has not yet been investigated whether our closest living relatives –chimpanzees– seek help strategically. In Study 1, we investigated whether chimpanzees seek help selectively when they need it. Chimpanzees (N=19) sought help when it was necessary, but not if they could solve the problem themselves (Chi2(1)=30.821, p<.001). In Study 2, we investigated whether chimpanzees seek help strategically: Do they consider action-related costs of potential helpers as much as they consider their own? Chimpanzees (N=14) had a preference for a low-cost option when they had to obtain a reward on their own, but not when they sought help from others (Chi2(1)=7.989, p=.005). These findings imply that chimpanzees seek help when they need it, but they do not strategically consider other’s costs when deciding whom to seek help from.

When referring to spatial arrangements of two objects in the visual field, German native speakers prefer reflectionas a subtype of the relative frame of reference. Whether this preference transfers to objects in one’s back and whether a mentalturn has to precede such dorsal references (turn hypothesis), has recently been explored in studies implementing questionnaires.However, the results hardly supported the turn hypothesis and rather suggested backward projection as an alternative strategy fordorsal references. To test the two assumptions more rigorously, a series of experiments implemented dorsal object arrangementsin interview situations and induced dorsal perspectives via turning, shifting or reflecting the actual view of participants. Acrossexperiments and conditions, backward projection consistently emerged as the preferred referencing strategy and only a smallproportion of dorsal references accorded with the turn hypothesis. Participants’ retrospective descriptions supported this patternand suggested backward projection to be involved in dorsal referencing.