The key element here is intervention. Animals learn by changing their environment. Superstition in pigeons arises because they believe their actions cause the

The key element here is intervention. Animals learn by changing their environment. Superstition in pigeons arises because they believe their actions cause the reward, it isnt "mere sequence". Any distribution over two variables observed overtime, for all time can change unpredictably given an environmental change. Animals have rich models of objects and their behaviour over time, these models aren't "sequential", and they are brought to bare on deciding whether mere sequences should be regarded causally.