I happened to catch this Q&A on the radio today, at the start of program segment about a course on "Shakespeare and Financial Markets":
|Q:||All right, right away can you make the link for us between Shakespeare's writings and economics?|
|A:||I- I think it's uh clear when you delve into Shakespeare —
and of course I've spent a lifetime looking at Shakespeare
and also you know being in the financial markets —
human behavior is behind so much of what we do in our lives,
and also most important in our decision making,
and Shakespeare held up a mirror to humans and
showed us how we behave, probably one of the first artists to really capture that.
And when you look at some of the mistakes,
both policy-wise and also by investors in the last twenty or so years,
you see a lot of those behaviors,
and so drawing out those connections is part of what made the course I think for-
for me and also for the students a lot of fun this year.
The literal meaning of behavior is something like "the manner of conducting oneself" or "the way in which someone behaves", and "human behavior" is therefore, roughly, "the way that people act". So can we rescue "Human behavior is behind so much of what we do in our lives" from tautology? After all, "human behavior" is literally just a polysyllabic term for "what we do in our lives".
It's possible that the speaker meant only to move from the personal ("what we do in our lives") to the universal ("human behavior" in general). But I think that something more is going on.
A Google Books search for "human behavior" turns up contexts like this, from the publisher's description of a textbook for medical students on Human Behavior:
… the biopsychosocial model in medical practice; culture, ethnicity, and the practice of medicine; psychoanalytic psychology; human sexual development and physiology; childhood and adolescent development; medicine and the family; the psychology and psychobiology of developmental trauma; and neurobiological aspects …
And of course there's B.F. Skinner's famous (or infamous) Science and Human Behavior, "a detailed study of scientific theories of human nature and the possible ways in which human behavior can be predicted and controlled". Or G.K. Zipf's Human behavior and the principle of least effort, where according to its abstract
After a brief elaboration of principles and a brief summary of pertinent studies (mostly in psychology), Part One (Language and the structure of the personality) develops 8 chapters on its theme, ranging from regularities within language per se to material on individual psychology. Part Two (Human relations: a case of intraspecies balance) contains chapters on "The economy of geography," "Intranational and international cooperation and conflict," "The distribution of economic power and social status," and "Prestige values and cultural vogues"—all developed in terms of the central theme.
As a result of decades of such use in academic contexts, it seems that for some people, the phrase "human behavior" has come to mean something like "psycho-social analysis of motivation and interaction".