Although human behavior is still weird, and highly fallable! Despite best interventions (therapy, drugs, education), sometimes they still kill each other and we aren't 100% sure why, or how to solve it.
That doesn't mean that the same level of study can't be done on AI though, and they are much easier to adjust compared to the human brain (RLHF is more effective than therapy or drugs!).
They are just a more familiar black box. AI’s are simpler in principle. And also entirely built by humans. Based on well-described mathematical theories. They aren’t particularly black-box, they are just less ergonomic than the human brain that we’ve been getting familiar with for hundreds of thousands of years through trial and error.