A recent body of research suggests infants prefer prosocial behaviours. However, some studies failed to report this preference, and asked what specific parameters allow to observe it. We attempt to provide a part of answer to that question by investigating if the preference vary 1) with age (testing infants aged 6, 12, 18 months), 2) with the type of social behaviours (help, play and share), and 3) when the pro-and antisocial agents' appearance were manipulated (i.e., displaying neutral, own-race or other-race faces). To this end, we use an eye-tracking methodology to assess infants' preference between pro-and antisocial agents featured in animated cartoons. We found that the prosocial preference was not stable across ages and varied depending on social scenarios. No sound conclusion could be given about the influence of faces. Our results invite to wonder in which extent very young infants perceive the prosociality in complex social behaviours.