Do you agree or disagree with the notion that "individuals with superficial knowledge of a topic or subject may be worse off than people who know absolutely nothing"?

It really depends on the subject. If my arm were cut off I’d take someone with superficial medical knowledge over the alternative.

Yes, I agree that they “may” be worse off.

For example, humans who think they know something about atomic power, or GMO’s, or how to semi-safely jump off a cliff, or plastic surgery, or who know a little about how to defend themselves, and so try these things out without enough caution…

If you know that your knowledge is superficial, then you are better off, since at least you know something about the subject.

In many cases, that is probably true. We tend to over-estimate our superficial knowledge of a given subject. Once we know a little, we believe there is not much left to learn.
(This phenomenom is called Dunning-Kruger-Effect.)

The illusion of vast knowledge makes us unlikely to accept advice and prone to seek out sources which confirm our beliefs, even if those are unfounded. We’re human. We hate to be wrong.

For myself, I agree. I tend to arrive at inaccurate conclusions or make poor decisions when my subject knowledge is limited.

As long as their superficial knowledge is accurate they would still be ahead of someone with no knowledge. It is the inaccurate, if not downright incorrect information that poses more danger than not knowing anything at all. haha

The anti-vaccination movement is a perfect example of superficial knowledge being dangerous.

It is a matter of how a person assesses their knowledge. A person completely ignorant of an area may feel that it is still possible to make a decision based on a hunch or intuition. I think it is more likely that someone with only partial information may get in over their head.

It depends. If the information is accurate and the person knows they have limited knowledge it can be just fine even better than knowing nothing.

However, it is true that sometimes a little knowledge is dangerous or can work against you.