Causation is the skill of explaining why historical developments happened and what they produced. On AP European History, a strong causation answer does more than list events in order. It identifies relevant causes or effects, weighs their importance, and explains the connection between evidence and the argument.

AP European History assesses Skill 5, Making Connections, in multiple-choice questions, at least one short-answer question, the DBQ, and the LEQ. The DBQ can draw from 1600-2001. LEQ choices usually cover 1450-1700, 1648-1914, or 1815-2001.

What Causation Requires

Good causation work usually has three parts:

Relevant cause or effect: Name a real factor that fits the time period and prompt.
Historical connection: Explain how that factor helped produce a later development or result.
Relative importance: Show why one cause or effect mattered more, less, or differently than another.

Avoid writing that something happened "because of many reasons" without naming the reasons. Also avoid treating correlation as causation. Two developments can happen around the same time without one directly causing the other.

How to Build a Causation Argument

Start by identifying the exact development in the prompt. Then make a quick list of possible causes and effects. Group them into categories such as political, economic, social, cultural, intellectual, diplomatic, or environmental factors. This helps you avoid a scattered paragraph.

For an LEQ or DBQ thesis, make a defensible claim that answers the prompt and ranks the causes or effects. For example:

Although several factors contributed to the development in the prompt, the most important cause was [specific cause] because [historical explanation].

The sentence does not need to sound fancy. It needs to make a claim that can be proven with evidence.

Subject-Specific Examples

Printing, humanism, and criticism of Church practices helped the Protestant Reformation spread beyond one local dispute.
Enlightenment ideas, fiscal crisis, social inequality, and political conflict helped cause the French Revolution.
Nationalism, alliances, imperial rivalries, militarism, and crisis diplomacy all contributed to the outbreak of World War I.

Each example includes a cause, a development, and a connection between them. To earn stronger reasoning points, explain the mechanism. Instead of saying "industrialization caused reform," explain how factory labor, urban crowding, and new class tensions pushed reformers or governments to respond.

Common Mistakes

Listing causes without ranking them: The prompt often asks for relative importance, so explain which factor mattered most and why.
Using vague evidence: Replace phrases like "new ideas" with specific evidence such as Enlightenment natural rights, republicanism, nationalism, or liberalism when those fit the topic.
Skipping the connection: Evidence only helps if you explain how it caused or resulted from the development.
Ignoring the time frame: Evidence outside the dates can provide context, but the core answer needs to stay inside the prompt's period.

Practice

Try this prompt: Evaluate the relative importance of causes of the Protestant Reformation in the period from 1450 to 1648.

Before writing, sort your evidence into at least three categories. Then choose the category that best explains the development and write one sentence explaining why it was more important than the others.