better than a lot of the stuff I had to read in college-level English classes...
otherwise, I suspect motivations may come into play:
the majority of people will act in their own interests if no one is hurt by it (1);
a minority of people will act in their own interests if people are hurt by it (2);
another minority will take a passive approach (3);
...
1: so the characters' responses are "fairly normal" in this sense. they will try to grab it, but let it slide if someone else manages to get it first.
2: say, someone else spots and reaches for the money, main character shoves them over or punches them out to get to it, or tries to grab it from them and get away before too much attention is raised.
3: they are willing to let someone else have it, but will probably still claim it if no one else does, others might decide whether or not to grab it based on whether or not anyone is likely to see them do so, ...
to some extent, this will vary some based on the value of the money, for example, more people will tend towards 2 if the value is greater (say, $1000), or towards 3 if it is less, say it is a $5 bill, ...
OTOH, a person might be more willing to help others based to some extent on how much they are likely to personally benefit from it, like if they will get something >= whatever they have to invest into it, though probably with some individual weighting factors (and typically based more on social barter than on explicit monetary values or material goods). like, say, a person that is nice to someone mostly for sake of trying to get something from them, a jerkface will just try to take it from them (using guilt, coercion, threats of violence, ...), and a "nice" person will usually leave it more optional as to whether or not there is any sort of payback, ...
similarly, peoples' behavior may be kept in check for sake of fear of retribution from others, ... (like, if harm is done to someone else, they are more likely to try to "get even" in one way or another, ...).
with pretty much all of this going on at a societal level, sort of making a large implicit social value-network (leading to the existence of things like laws and governments, police forces, various military organizations, ...).
or such...