Learning by Observation Emerges from Simple Associations in an Insect Model

SummaryRecent debate has questioned whether animal social learning truly deserves the label “social” [1]. Solitary animals can sometimes learn from conspecifics [2 and 3], and social learning abilities often correlate with individual learning abilities [4, 5 and 6], so there may be little reason to view the underlying learning processes as adaptively specialized. Here, we demonstrate how learning by observation, an ability common to primates, birds, rodents, and insects [7, 8 and 9], may arise through a simple Pavlovian ability to integrate two learned associations. Bumblebees are known to learn how to recognize rewarding flower colors by watching conspecifics from behind a screen [9], and we found that previous associations between conspecifics and reward are critical to this process. Bees that have previously been rewarded for joining conspecifics copy color preferences, but bees that lack such experience do not, and those that associate conspecifics with bitter substances actively avoid those flower colors where others have been seen. Our findings place a seemingly complex social learning phenomenon within a simple associative framework that is common to social and solitary species alike.

► We test whether second-order conditioning underlies bee social learning
► Bees that associate conspecifics with appetitive stimuli copy, but naive bees don’t
► Bees that associate conspecifics with aversive stimuli avoid popular colors
► Any animal that can integrate learned associations could potentially learn socially