Aggressiveness is a measure of how "mean" or "nice" a civilization is. More aggressive civilizations are more likely to attack first, extort other civilizations for money, and hold a grudge. Development is a measure of the balance a civilization creates between building up existing cities and expanding. Civilizations which are more expansionistic will tend to colonize until there is no land left, and then go to war if necessary to keep expanding. Civilizations which are more perfectionistic will tend to build large, well defended cities. Militarism is a measure of how much a civilization favours building military units over self-improvement.