Final answer:
The reasoning presented in the question is invalid because the conclusion does not logically follow from the premises.
Step-by-step explanation:
The reasoning presented in the question is invalid. While it is true that some human beings are gullible and some human beings enjoy circus tricks, it does not necessarily follow that some gullible humans enjoy circus tricks. This is an example of an invalid deductive inference where the conclusion does not logically follow from the premises.