"S. apella" tool manufacture and use has been analyzed for potential clues to social learning and problem solving ability, as tool manufacture and use can often shed light on such complex cognitive abilities. Social learning, or the ability to learn from other individuals, is a controversial topic in most nonhuman species like "S. apella" because of the relative difficulty of determining whether a behavior was learned from imitation or a much simpler form of social learning. One way of closing the gap between concurrent tool related behaviors and their likelihood of arising from imitation is by narrowing down events that would make social learning more probable such as a preference for observing experienced tool users. In this regard, Ottoni and his team found that young capuchins tended to observe the best tool users when cracking nuts. Another way of isolating imitation from other simpler behaviors is to present the capuchins with a box that has food but has two different ways of opening it. The important point is that neither way should be more advantageous so that the monkey can freely choose one. In one such study, when humans opened the door in front of the monkeys using one way only, the monkeys used that method, even when they discovered the alternative on their own. In another study, capuchin alphas from two separate groups were trained to open the door in a specific way, after which the monkeys were paired with subordinates who learned to open the door in the same way. When capuchins are trained in the same way and this time released into their groups, the habit is once again disseminated amongst all group members even when others discover alternative ways. Nevertheless, the subject of whether or not "S. apella" learns by imitation is still controversial, because of the inherent difficulty in teasing out unambiguous evidence of a complex cognitive process such as imitation.