Aggression

Aggression has several definitions. We begin with common ones in dictionaries such as American Heritage, Webster, or Oxford, the last of which gives us the seventeenth century definition of an unprovoked attack or assault, the eighteenth century definition of beginning a quarrel or war, and the twentieth century definitions of behavior intended to injure another person or animal or forceful self-assertion.

There are at least five types of definition. Conceptual definitions identify something in terms of hypothetical criteria, such as defining aggression as a feeling of anger combined with a wish to harm another. A definition by synonym might be threatening or carrying out violence against another.

A third is to describe operations required for the phenomenon to occur, such as aggression as the result when two or more persons have the same goal, but only one can attain it. A fourth type of definition describes how something operates or behaves, such as defining aggression as acting out, fighting, or speaking abusively. If it occurs, it is directly observable by others. A fifth defines something in terms of qualities, traits, or characteristics. It specifies internal characteristics rather than behaviors, so requires collecting data directly from subjects, whether by physiological measures such as blood pressure or by self-report.

The last three are the most useful if one is taking a scientific approach. Each is an “operational definition,” one that makes it possible to distinguish, observe, and measure phenomena of interest. However, each requires different methods for doing so. Awareness of different sorts of definition helps recognize each and understand why a term may be defined in more than one way. Some conflicts arise simply because people mean different things by the same term. Therefore, it is important to be as precise as possible in what we mean by our terms.