Psychological essentialism is a folk theory characterized by the belief that a causal internal essence or force gives rise to the common outward behaviors or attributes of a category's members. In two studies, we investigated whether 4‐ to 7‐year‐old children evidenced essentialist reasoning about heart transplants by asking them to predict whether trading hearts with an individual would cause them to take on the donor's attributes. Control conditions asked children to consider the effects of trading money with an individual. Results indicated that children reasoned according to essentialism, predicting more transfer of attributes in the transplant condition versus the non‐bodily money control. Children also endorsed essentialist transfer of attributes even when they did not believe that a transplant would change the recipient's category membership (e.g., endorsing the idea that a recipient of a pig's heart would act pig‐like, but denying that the recipient would become a pig). This finding runs counter to predictions from a strong interpretation of the “minimalist” position, an alternative to essentialism.