In "Alice and Bob's contrary behavior served to" vs "Alice's and Bob's contrary behavior served to"
Usually the choice between the two forms hinges on whether the two actors possess the subject in common. And usually behavior cannot be jointly owned. So my intuition is that this choice hinges on whether Bob and Alice are treated as a group or as individuals. Is that correct, or are there other considerations?
So I might use the first form if Alice and Bob are acting united relative to a third party or the second form if they are behaving contrary to each other or to many other parties separately.
This question is distinct from Third-Person Possessive Pronouns in Dual Possessives because behavior is an uncountable noun that cannot usually be co-owned and because this question does not involve pronouns. The linked question does not answer this one.