This post is written to accompany the lesson on Phineas Gage and the frontal lobe in “IB Psychology: A Student’s Guide.” 

  • Unit: Criminology
  • Topic 1: The Brain and Behaviour
  • Lesson (a): “The Frontal Lobe

The guiding question for this lesson is designed to give you some practice at explaining the results of a study. The question is:

“How does Phineas Gage’s case suggest that damage to the frontal lobe affects impulsive behaviour?”

Here’s what a typical first attempt looks like:

Phineas Gage had an accident working as a railroad worker. A metal pole shot through his skull and damaged his frontal lobe. After this, Gage’s behaviour changed and he went from being a mild-mannered man to being “no longer Gage.” For example, he wasn’t allowed to be around women as he would say rude things to them. This shows that damage to the frontal lobe affects impulsive behaviour.

This is a common way that students write about research. There’s nothing wrong with describing the details, as these are necessary for a good explanation. The weakness in this answer is that it demonstrates limited analysis and application. It states the conclusion, but it doesn’t quite explain it. Analysis means to break things down to see how they’re related. A good explanation communicates this analysis by showing how things are related in response to the question. It’s the first and final sentences that needs tweaking so the details are more closely applied to the question.

Psychology studies are about relationships between variables, so you must make it clear how the relationship is shown in the study in order to apply this to demonstrate a particular concept. The concept in this case is that damage to the brain can affect impulsive behaviour.

Here’s a better explanation that includes more detailed analysis and application:

Gage’s study suggests that damage to the brain can affect impulsive behaviour because his behaviour changed as a result of an accident that damaged his frontal lobe. Before the accident Gage was mild-mannered, but after the accident his behaviour changed and he seemed to be more impulsive as he was “no longer Gage” and he couldn’t be around women for fear he would say rude things to them. It is this change in Gage’s ability to regulate his impulsive actions as a result of the accident that suggests damage to the frontal lobe can affect impulsive behaviour.

Both answers are very similar and it’s only a slight difference between them. The difference is that the first answer doesn’t quite show how Gage’s case can address the question: it just concludes that it can and it leaves the reader to figure out for themselves how the results of the study demonstrate the concept.

The second answer shows more clearly how the case can show the concept, by highlighting that it was the change in behaviour resulting from the brain damage that enables the conclusion to be drawn. This happens in the first and last sentences.

While the difference might seem minor and trivial, it will become important in exam answers. Sometimes two or three sentences are what separate a mediocre short answer response from an excellent one. Those two or three sentences are the explanation that show your understanding of the study and how you can use the study to address the particular question. In short, your explanation includes the analysis (how things are related) and application (using the relationship to answer the question).

Clear explanations convey your understanding, so it is important that you communicate how things are related. In this case, it’s showing how the frontal lobe damage is related to the impulsive behaviour, and also how this is shown in Gage’s case.