Anger-in is a measure of the tendency to internally experience anger. The variable is assessed using 8 items from the State-Trait Anger Expression Inventory. Participants are asked to respond yes = 1 if the statement describes how they generally feel or no = 0. Anger-in is computed as the number of items answered in the direction indicative of the trait and ranges from 0 to 8, with higher scores indicating a greater tendency to internally experience anger.

Participants are presented the following items:

When angry or furious...

1. I keep things in.
2. I pout or sulk.
3. I withdraw from people.
4. I boil inside, but I don't show it.
5. I tend to harbor grudges that I don't tell anyone about.
6. I am secretly quite critical of others.
7. I am angrier than I am willing to admit.
8. I am irritated a great deal more than people are aware of.

Note: If 3 or more items are missing, angerin is not computed.