This sketch of an account of human nature begins with the claim that we should see humans as a kind of process, a life cycle, rather than as a kind of substance or thing. A particular advantage of such a process perspective is that it readily accommodates the developmental plasticity that has been an increasingly important concept in recent biological theory. Human behaviour, on this account, should be understood as providing adaptive and flexible responses to an unpredictable environment. It is, therefore, generally misguided to provide a standard account of human nature in terms of behaviour or behavioural dispositions. If there is such a thing as human nature it is a uniquely refined propensity for novel and unpredictable behaviour.