There are two different questions being asked here. The one in the title, can we impute goals to organisms based on behavior, is a clear yes. Behavior provides the main data we work off of for imputing goals.
The second question is at the end of the discussion, can goals be REDUCED to behavior, as per the discussion of attractors, inhibitors, etc. The answer on this reductionism is a NO. And this is because, to infer goals, we are NOT only looking at behavior, we are also looking internally, at our own minds, and extrapolating off our internal intentionality and inferring a theory of mind for other agents too. This internally based inference is NOT just a replication of our own minds, but also involves speculative thinking about how other minds can be different from our own, is a significant secondary source of data, and is what allows us to understand complex motives, and deception.
The attempt to reduce mind to behavior alone is what was central to the philosophic and psychological movement called behaviorism. As a psychological theory, behaviorism is really only useful for very simple creatures that do not have awareness of the intentionality of other creatures. Behaviorism tried to do psychology without Theory of Mind, and has mostly been abandoned as an extended bizarre failure. Since awareness of the intentionality of other creatures is central to psychology it was basically an effort to abandon/ignore the psycho part of psychology.
