Those are not complex behaviors. An instinct is a complex behavior, like migrating for the winter or building a nest.
The problem with claiming that humans have instincts is that it gives cover for bad theories of mind. For instance, the Nazis believed Jewish people have Jewish minds and German people have German minds; many Marxists have held that bourgeoisie have bourgeois minds. In reality, the human mind is a blank slate, in terms of knowledge and beliefs.
