Impulsivity

Abusing drugs can lead to impulsivity and aggression.

Yanni had a history of impulsivity.

Sociopaths are driven by impulsivity.

In reliable environments, waiting to eat a second marshmallow is likely to be beneficial. However, in environments in which rewards are uncertain, such as when experimenters are unreliable, eating the single marshmallow right away may be beneficial. Thus, impulsivity can be understood as an adaptive response to the contingencies present in an unstable environment rather than a moral failure in which animalistic drives overwhelm human rationality.