Theoretical ideas and empirical research have shown us a seemingly surprising result: children, even very young toddlers, demonstrate learning and thinking in a strikingly similar manner to scientific reasoning in formal research. Encountering a novel phenomenon, children make hypotheses against data, conduct causal inference from observation, test their theory via experimentation, and correct the proposition if inconsistency arises. Rounds of such processes continue until the underlying mechanism is found. Towards building machines that can learn and think like people, one natural question for us to ask is: whether the intelligence we achieve today manages to perform such a scientific thinking process, and if any, at what level. In this work, we devise the EST environment for evaluating the scientific thinking ability in artificial agents. Motivated by the stream of research on causal discovery, we build our interactive EST environment based on Blicket detection. Specifically, in each episode of EST, an agent is presented with novel observations and asked to figure out all objects’ Blicketness. At each time step, the agent proposes new experiments to validate its hypothesis and updates its current belief. By evaluating Reinforcement Learning (RL) agents on both a symbolic and visual version of this task, we notice clear failure of today’s learning methods in reaching a level of intelligence comparable to humans. Such inefficacy of learning in scientific thinking calls for future research in building humanlike intelligence.